Ch_3BranchiniB

Chapter 3, Section 1
toc
 * What do you think?**
 * You can protect yourself from serious injury should an accident occur by having an opposite action acting upon and something that helps you stay in place or resist going forward. A seat belt is a great example for this. You must wear one to be safe.


 * Investigate**

1. Quia Survey

2. a) After taking the quiz, I got 9 out of 15 questions correct. Speaking in the textbook terms, I actually ended up being a Novice Analyst. Some of the facts were confusing and can go either way. I was not really surprised about my grade, as I thought I would get around that grade. My knowledge is average when it comes to these facts.

3. (yes/no) || New Cars (1,2,3) ||
 * ** Safety features ** || Means of protection || Pre-1960 cars
 * seat belts || to prevent the driver or passenger from propelling forward || No || 1, all ||
 * head restraints || prevents you from getting whiplash || No || 1, all ||
 * front airbags || to prevent you from flying out of the car/cushions during a collision || No || 1, all (driver's side) ||
 * back up sensing system || allows people to see in blind spots when backing up || No || 3, few ||
 * front crumple zones || increase collision during reducing impact || No || 1,2,all, some ||
 * rear crumple zones || increase collision during reducing impact || No || 2, some ||
 * side-impact beams in doors || resists side penetration || No || 2, some ||
 * shoulder belts for all seats || keeps passengers in seats during collision || No || 1, all ||
 * anti-lock braking systems (ABS) || helps maintain control/ prevents skids || No || 2, some ||
 * tempered shatterproof glass || helps prevent cuts || Yes || 1, all ||
 * side airbags || protects head/ torso in side collisions || No || 2, some ||
 * turn signals || warns other drivers of your direction || Yes || 1, all ||
 * electronic stability control || helps resist rollovers || No || 2, 3, some, few ||
 * energy-absorbing collapsible steering column || prevents chest trauma || No || 1, all ||


 * Physics Talk**


 * Summary:** In this physics talk, we analyzed vehicle safety. When in an vehicle, people are not the only ones in danger; the pedestrians are in danger, as well. Governments and manufacturers should work together to improve and be aware of the safety of a vehicle. When in an accident, when your vehicle has high safety, your injury will be minor. Ralph Nader wrote, //Unsafe at any speed, to depict the dangers of driving without a seatbelt, having chrome dashboards, and solid steering columns. Four wheel drive increase accidents because drivers have the tendency to speed thinking that all the safety features will serve as protection. //

1. Three ways that manufacturers have made vehicles safer include seat belts, front air bags, and back up sensing systems. 2. There are greater numbers in kilometers traveled and how the driver is under the impression that the features will protect them, thus, they speed.
 * Checking Up**

1. 10 safety features include: front air bags (F), side of car air bags (S) , back up sensing system (R) , head restraints (F,R) , front crumple zones (F) , rear crumple zones (R) , shoulder belts (F,R,S,T) , side impact beams (S) , electronic stability control (T) , seat belts (F,R,S,T) 2. Bike safety features include: elbow pads, knee pads, reflector, and helmet 3. In-line skating features include: helmet, wrist guards, knee pads, and elbow pads 4. Skateboard features include: helmet, wrist guards, knee pads, sneakers
 * Physics To Go**


 * What do you think now?**
 * After reading this section, safety features become more clear. In order to protect myself from serious injury, I would make sure the vehicle had all the necessary safety features from seat belts to air bags. Right away, I would put on my seat belt because it holds the most protection and it is the easiest part of being safe. You should use your turn signals to show direction. You should realize that the car is a weapon and if you do not handle properly, you might be danger.

Chapter 3, Section 2
**Investigate X2: Newton's FIrst Law and Seatbelts**

Objectives:
 * What happens to a passenger involved in a car accident without and with a seatbelt?
 * Without a seatbelt, a passenger involved in a car accident would be severely injured or killed. With a seatbelt, the passenger will be able to stay in the seat without propelling forward.
 * What factors affect the passenger’s safety after a collision?
 * Factors include the ability to get out of the car if the car is flipped.
 * How would a seat belt for a race car be different from one available on a regular car?
 * A seatbelt in a race car must be different because you are traveling at a much higher speed so the restriction of the seat belt must be larger than of a car.

Hypothesis: Respond to each of the above objectives fully.

Materials: List any materials used and draw a labeled diagram of your set-up (alternatively, include a snapshot or video).
 * Clay, textbooks, ramp, yarn, and meter stick**

Procedure:
 * 1) Make a clay figure and then place the figure in the cart.
 * 2) Arrange a ramp so that the endstop is at the bottom of the ramp.
 * 3) Adjust the height of the ramp to make a very shallow incline.
 * 4) Send the cart down the ramp.
 * 5) Very gradually increase the height of the ramp until significant “injury” happens to your figure. Make a note of this height.
 * 6) Fix your clay figure. Create a seatbelt for the figure and take a "Before" picture and post in your data table.
 * 7) Send your cart and passenger down the ramp at the same height as in Step 5. Be sure to record your observations specifically and carefully. Take an "After" picture and post in your data table to supplement your written observations.
 * 8) Repeat Steps 6 and 7, using different types of material for the seatbelt.

Data and observations:

Injury Height with no seatbelt: .085 m through his body and sliced his neck. || 6 ||
 * **//Type of Seatbelt//** || //**Before Picture**// || //**After Picture**// || //**Description and Observations**// || //**Group**// ||
 * Thread || [[image:proringer:theadmadread.jpg height="192" caption="theadmadread.jpg"]] || [[image:proringer:thread_madread_2.jpg height="192" caption="thread_madread_2.jpg"]] || Arm chopped off. The seat belt cut
 * Wire || [[image:proringer:hershey_kissboybefore.jpg height="192" caption="hershey_kissboybefore.jpg"]] || [[image:proringer:hersheykissafter.jpg height="189" caption="hersheykissafter.jpg"]] || The wire was wrapped around him pretty tightly. The passenger was severely injured because the wire sliced through his arms and chest. It is clearly the thin dense material that did this || 1 ||
 * Yarn || [[image:proringer:bj_string_one.jpg height="192" caption="bj_string_one.jpg"]] || [[image:proringer:bj_string_twozel.jpg height="192" caption="bj_string_twozel.jpg"]] || Our observation of the string seat belt is that when the accident occurred, the figure slammed forward. This shows that the string is not sturdy enough to prevent an injury in an accident || 5 ||
 * String || [[image:proringer:stringlapoop.jpg height="192" caption="stringlapoop.jpg"]] || [[image:proringer:stringlapoop2.jpg height="192" caption="stringlapoop2.jpg"]] || Our seatbelt made of string went around the chest. After going down the ramp, our passenger was still in the cart without any injuries. || 2 ||
 * Ribbon || [[image:proringer:panso_x3_ribbon.jpg height="192" caption="panso_x3_ribbon.jpg"]] || [[image:proringer:panso_ribbon_x4.jpg height="192" caption="panso_ribbon_x4.jpg"]] || We made a seatbelt out of ribbon that went around his waist shoulders and chest. When the cart went down the ramp, the seatbelt held him in place and the clay person didn't leave the cart. || 3 ||
 * Masking Tape || [[image:proringer:mitchel_lalalal_masking.jpg height="192" caption="mitchel_lalalal_masking.jpg"]] || [[image:proringer:michell_lalal_2_masking.jpg height="192" caption="michell_lalal_2_masking.jpg"]] || e took a piece of tape and folded it over so there was no sticky part. We then twirled the end to make tying it easier. We put the tape belt around "her" waist and tied it around the bottom of the cart. Despite my face in the after picture, the tape actually worked well because our figure was unharmed and barely moved. || 4 ||

// *Read the Physics Talk p268 - 271 before answering the following questions. * // Questions:
 * 1) Define the terms: inertia, force and pressure.
 * 2) In the collision, the car stops abruptly. What happens to the “passenger”?
 * 3) <span style="font-weight: normal; margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">What parts of your passenger were in greatest danger (most damaged)?
 * 4) <span style="font-weight: normal; margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">What does Newton’s first law have to do with this?
 * 5) <span style="font-weight: normal; margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">What materials were most effective as seatbelts? Why?
 * 6) <span style="font-weight: normal; margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">Use Newton's first law of motion to describe the three collisions.
 * 7) <span style="font-weight: normal; margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">Why does a broad band of material work better as a seatbelt than a narrow wire?

Answers

1. Inertia is the natural tendency of an object to remain at rest moving with constant speed in a straight line. Force is an interaction between two objects which can result in an acceleration of one or both. Pressure is the force per area where the force is normal and directed perpendicular to the surface, measured in N/m^2 or Pa (pascals). 2. The passenger propels forward. This leads to injuries. 3. In our experiment, the head was in the most danger because he propelled forward and ultimately, would have went through the windshield. Also, it depends on where you hit from. 4. Newton's law states that anything will move in a straight line motion until an unbalanced force is acting. In this case, the passenger abided by the law, but ultimately, an unbalanced force would be present. 5. The most effective materials included the ribbon because it was the strongest material. It was wrapped in tightly to prevent the passenger from propelling forward. 6. First Collision - The automobile strikes the pole. The pole exerts the force that brings the automobile to rest. Second Collision - When the automobile stops, the body keeps moving. The structure of the car is the force that stops the passenger from moving. Third Collision - Although the body stops inside, organs continue to move and the body wall exerts the force for them to stop moving. 7. The broad band of material work better as a seatbelt because it is more thick and stronger. There is a much larger area of contact, as well.

Conclusion:


 * Using Newton's First law of Motion, explain why a seat belt is an important safety feature in a vehicle. What factors affect the effectiveness of a seatbelt? What would you need to consider when designing a seatbelt for a race car? Use specific observations from this investigation to support your answers to these questions.
 * A seatbelt is an important safety feature in a vehicle because it restricts you from propelling forward. It keeps the passenger in the seat, so that they won't go in a straight line motion and have an unbalanced force act upon them. Seat belts should be snug and you must feel secure in the seat with the seat belt tightly around you. The material should have low pressure. Race car drivers should have tighter seat belts due to the high speeds. In my experiment, the best material was ribbon because it was wider and thicker.
 * Explain at least 1 cause of experimental error. Be sure you describe a specific reason.
 * One cause of experimental error would be that the clay man could have driven down different slopes. Also, the clay man could have had his bottom stuck to the seat.
 * How would you improve the results of this lab? (In other words, what would you change about the materials or procedure to eliminate or reduce the experimental error you describe above?
 * Maybe the group should have tied all their people with the same tightness. We should not have made our guys tied in so tightly. We could have had all the same slopes and used the same guy.

Chapter 3, Section 3
<span style="font-size: 1.3em; margin: 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 5px;">Investigate X3: Energy and Air Bags


 * Objective:**
 * <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">How does an air bag protect you during an accident?
 * <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">An air bag prevents you from the impact of the crash.


 * Hypothesis:** Respond to the objective fully.
 * Materials:** List any materials used and draw a labeled diagram of your set-up (alternatively, include a snapshot or video).
 * egg, bowl, flour, meter stick, plastic bag, scale**


 * Procedure:**

**Note: //You may want to use the available technology to take "Before" and "After" pics to post in your data table to assist and elaborate on your written descriptions.//**

// 1. Measure the height of your egg #1. // // 2. Place an egg in a ziplock bag, squeezing out all of the air in the bag before sealing. // // 3. Hold a ruler up on the table vertically. Hold the egg vertically at the 2 cm mark. (Keep the excess bag on top.) Drop it. Record your observations. // // 4. Hold the egg the same exact way at the 4-cm mark and repeat. Continue this process until the egg shell is slightly cracked. // // 5. Continue until the egg is smashed and the yolk leaks out. Measure the amount of egg still undamaged. How much of the egg is smashed? Be sure to record detailed observations. // // 6. Fill a bowl with rice and place the bowl inside of the box lid. // // 7. Measure the height of your egg #2. // // 8. Drop the egg from the smash height (Step 3). Measure the amount of egg sticking up out of the rice bed. How much of the egg is buried in the rice? Also, record your observations. // // 9. Repeat this, increasing the height in 2-cm increments until the egg is cracked, and then smashed. //

//**Data and observations:** Add more columns/row as needed.//
 * **Egg #** || **Drop Height** || **Cracked or Smashed?** || **Description and Observations** || **Mass (kg)** || **Height of Egg After Drop (m)** || **Total Damage or Sinkage (m)** ||
 * 1 || 2 cm. || The egg cracked. || The egg slightly cracked on the point of impact. || 0.055 || 0.060 || 0 ||
 * 1 || 4 cm. || The egg cracked. || The egg had a more severe crack at the point of impact. || 0.055 || 0.060 || 0 ||
 * 1 || 6 cm || The egg CRACKED || The egg became indented. || 0.055 || 0.058 || 0.002 ||
 * 1 || 8 cm. || THE EGG cracked.... || More indentation and cracks. || 0.055 || 0.056 || 0.004 ||
 * 1 || 10 cm || The egg cracked || The egg is in a cracked state. Most of the egg is cracked. || 0.055 || 0.056 || 0.004 ||
 * 1 || 12 cm || Cracked || The egg is still cracked and white oozed out || 0.055 || 0.055 || 0.005 ||
 * 1 || 14 cm || Severely cracked. || Cracked to the point of major oozing || 0.055 || 0.050 || 0.010 ||
 * 1 || 16 cm || Smashed || The yolk is completely out. || 0.055 || 0.045 || 0.015 ||
 * 1 Pt. 2 || 16 cm || No cracks at all. || The egg sank about 0.016 m. || 0.0564 || 0.040 || 0.016 ||
 * 1 Pt. 2 || 20 cm || No cracks at all. || The egg sank about 0.021 m. || 0.0564 || 0.035 || 0.021 ||
 * 1 Pt. 2 || 24 cm || No cracks at all. || The egg sank about 0.024 m || 0.0564 || 0.032 || 0.024 ||
 * 1 Pt. 2 || 28 cm || No cracks at all. || The egg sank about 0.025 m. || 0.0564 || 0.031 || 0.025 ||
 * 1 Pt. 2 || 2 m || No cracks || The egg sank about 0.028 m || 0.0564 || 0.028 || 0.028 ||
 * 1 Pt. 2 || 2.5 m || The egg finally cracked from an outrageous height. || The egg had cracks surrounding it. It exploded. It sank down right to the end of the plate about 0.030 m. || 0.0564 || 0.026 || 0.030 ||

>> Part II >> >> **Part II:** >>
 * Calculations:** Show equation(s), numbers plugged in, and answer with correct units. Add columns in your data table to include these results.
 * <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">What is the gravitational potential energy in each trial?
 * **Part I:**
 * = Trial ||= GPE (mgh) ||= Answer (Joules) ||
 * 1 || (.055g)(9.8m/s sq.)(2cm) || 10.78 ||
 * 2 || (.055g)(9.8m/s sq.)(4cm) || 21.56 ||
 * 3 || (.055g)(9.8m/s sq.)(6cm) || 32.34 ||
 * 4 || (.055g)(9.8m/s sq.)(8cm) || 43.12 ||
 * 5 || (.055g)(9.8m/s sq.)(10cm) || 53.90 ||
 * 6 || (.055g)(9.8m/s sq.)(12cm) || 64.68 ||
 * 7 || (.055g)(9.8m/s sq.)(14cm) || 75.46 ||
 * 8 || (.055g)(9.8m/s sq.)(16cm) | || 86.24 ||
 * = >> Trial ||= GPE (mgh) ||= Answer (Joules) ||
 * 1 || (.564g)(9.8 m/s sq.)(16cm) || 88.44 ||
 * 2 || (.564g)(9.8 m/s sq.)(20cm) || 110.54 ||
 * 3 || (.564g)(9.8 m/s sq.)(24cm) || 132.65 ||
 * 4 || (.564g)(9.8 m/s sq.)(28cm) || 154.76 ||
 * 5 || (.564g)(9.8 m/s sq.)(200cm || 1,105.44 ||
 * 6 || (.564g)(9.8 m/s sq.)(250cm) || 1,381.80 ||
 * <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">How much work is done in each trial?
 * **Part I:**
 * = Trial ||= Work (F * d) ||= Answer (Joules) ||
 * 1 || (.539N)(2cm) || 1.08 ||
 * 2 || (.539N)(4cm) || 2.16 ||
 * 3 || (.539N)(6cm) || 3.23 ||
 * 4 || (.539N)(8cm) || 4.31 ||
 * 5 || (.539N)(10cm) || 5.39 ||
 * 6 || (.539N)(12cm) || 6.47 ||
 * 7 || (.539N)(14cm) || 7.55 ||
 * 8 || (.539N)(16cm) || 8.62 ||
 * 8 || (.539N)(16cm) || 8.62 ||
 * Trial || Work (F * d) || Answer (Joules) ||
 * 1 || (.553)(16cm) || 8.85 ||
 * 2 || (.553N)(20cm) || 11.06 ||
 * 3 || (.553N)(24cm) || 13.27 ||
 * 4 || (.553N)(28cm) || 15.48 ||
 * 5 || (.553N)(200cm) || 110.60 ||
 * 6 || (.553N)(250cm) || 138.25 ||
 * <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">How much force was used to stop the egg in each case of steps 5, 8 and 9.
 * We did not use any force.

** *Read the Physics Talk p279 - 287 before answering the following questions. * **
 * Questions:**
 * 1) <span style="margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">This investigate is an analogy for a person in an automobile collision. What does the egg represent? What does the table represent? What does the rice represent?
 * 2) <span style="margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">Define the terms: Kinetic Energy and Work.
 * 3) <span style="margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">What factors determine an object's kinetic energy?
 * 4) <span style="margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">WHen work is done on an object, what is the effect on the object's kinetic energy?
 * 5) <span style="margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">How does the force needed to stop a moving object depend on the distance the force acts?
 * 6) <span style="margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">What difference does a soft landing area make on a passenger during a collision?
 * 7) <span style="margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">How does a cushion reduce the force needed to stop a passenger?
 * 8) <span style="margin-bottom: 0px; margin-left: 37pt; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px; text-indent: -19pt;">What does the law of conservation of energy have to do with this?

Answers

1. The egg would represent the head. The table would represent the cars windshield. The rice would represent the air bag. 2. Kinetic Energy is defined to be the energy that an object in motion contains. Work is the exertion of force on an object over some distance. 3. Factors that determine an object's kinetic energy is mass and velocity. 4. When work is done on an object, the effect on the object's kinetic energy is either decreasing or increasing. This all depends on the direction of the applied force and the distance that the object is moving. 5. The object that is stopping has kinetic energy that needs to have a different energy, which is work. The greater the distance, the less force exerted, thus the smaller the distance, the stronger the force. 6. It makes for more distance to stop. This makes it much safer. It is also a much softer landing. 7. Cushions yield a larger landing distance. This means there is a less and softer force. 8. This states that an object in motion will stay in motion unless acted upon by an unbalanced. During a collision, the passenger is the object in motion and is stopped by the unbalanced force of the air bag.


 * Conclusion:**
 * · **Using the law of conservation of energy, explain how an air bag can protect you during an accident. Use specific observations from this investigation to support your answers to these questions.**
 * Due to the idea of the law of conservation of energy, the object in motion will stay in motion unless acted upon by an unbalanced force. The driver will go through the windshield if there is no unbalanced force acting upon it. Thus, there is the air bag. The air bag inhibits the driver from propelling forward through the windshield. It is the unbalanced force. Also, the air bag is soft and covers a lot of distance, yielding a softer and lesser force.
 * **·** **Explain at least 1 cause of experimental error. Be sure you describe a specific reason.**
 * One experimental error would measuring the displacement and change in height. In order to measure the impact distance, we would need to use a tool that is smaller than a meter stick. The flour also tends to change in position.
 * **·** **How would you improve the results of this lab? (In other words, what would you change about the materials or procedure to eliminate or reduce the experimental error you describe above?**
 * In order for consistency, I would use a different material or product other than flour. The position kept changing which meant results may be a little off. Using some sort of material that has the softness of the air bag would be much easier.

Chapter 3, Section 5

 * Investigation: See Group Wiki**


 * Physics To Go**

Investigate X6: Momentum and Inelastic Collisions

Objective: What physics principles do the traffic-accident investigators use to "reconstruct" the accident?
 * They take the use of force and momentum into account. They differ the masses and velocities to see the affects of it.**

Materials: List any materials used and draw a labeled diagram of your set-up (alternatively, include a snapshot or video). Procedure:

//**Data and observations:** Add more columns/row as needed//
 * 1) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Place a motion detector at the right end of a track. Open up data studio. Dump "Velocity" into "Graph" display, and enlarge this.
 * 2) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Place a cart on the middle of the track with the velcro to the right. Call this the "target cart." Place a second identical cart on the right end of the track. Call this the "Bullet cart".
 * 3) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Click "Start" on Data Studio, and then push the bullet cart very gently towards the target cart so that they collide and stick together. You may need to practice this a few times. Be sure to get your body out of the way of the motion detector!
 * 4) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Examine the graph produced by the motion detector. Using the Smart Tool, find the velocity right before and right after the collision. Record this in your data table.
 * 5) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Vary the masses of the carts and repeat the process 5 times.


 * **Mass of Bullet Cart (kg)** || **Mass of Target Cart (kg)** || **Speed of Bullet Cart**(m/s) || **Speed of Target cart (m/s)** || **Combined masses (kg)** || **Final Velocity of both carts (m/s)** ||
 * .502 || .494 || .57 || 0 || .996 || .27 ||
 * 1.002 || .494 || .47 || 0 || 1.496 || .25 ||
 * .502 || .994 || .56 || 0 || 1.496 || .19 ||
 * 1.002 || .994 || .36 || 0 || 1.996 || .14 ||
 * 1.502 || .494 || .43 || 0 || 1.996 || .24 ||

>> 1. p = (.501)(.85)= 0.426 km(m/s) >> 2. p = (.726)(.84)=0.609 kg(m/s) >> 3. p = (1)(.65)=0.65 kg(m/s) >> 4. p = (1.25)(.79)=0.988 kg(m/s) >> 5. p = (1.5)(.75)= 1.125 kg(m/s) >> 6. p = (1)(.76)= .76 kg(m/s) >> 1. p = (.499)(0)= 0 kg(m/s) >> 2. p = (.499)(0)= 0 kg(m/s) >> 3. p = (.499)(0)=0 kg(m/s) >> 4. p = (.499)(0)= 0 kg(m/s) >> 5. p = 1(0)=0 kg(m/s) >> 6. p = 2(0)=0 kg(m/s) >> 2. .609+0= .609 kg(m/s) >> 3. .65+0= .65 kg(m/s) >> 4. .988+0= .988 kg(m/s) >> 5. 1.125+0= 1.125 kg(m/s) >> 6. .76+0= .76 kg(m/s) >> 1. p= (1.009)(.42)= 0.424 kg(m/s) >> 2. p= (1.225)(.49)= 0.6002 kg(m/s) >> 3. p= (1.499)(.5)= 0.7495 kg(m/s) >> 4. p= (1.749)(.61)= 1.0669 kg(m/s) >> 5. p= (2.5)(.45)= 1.125 kg(m/s) >> 6. p= (3)(.31)= 0.93 kg(m/s)
 * Calculations:** Show equation(s), numbers plugged in, and answer with correct units. Add columns in your data table to include these results.
 * 1) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Find the initial momentum of the bullet cart for each trial.
 * 2) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">p= mv
 * 1) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Find the initial momentum of the target cart for each trial.
 * 2) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">p=mv
 * 1) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Find the sum of the initial momenta of the two carts for each trial.
 * 2) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">p = mv
 * 3) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">1. 0.426+0= .426 kg(m/s)
 * 1) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Find the final momentum of the combined carts for each trial.
 * 2) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">p=mv

** *Read the Physics Talk p312 - 315 before answering the following questions. * **
 * Questions:**
 * 1) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Compare the initial momenta (calc 3) to the final momentum (calc 4). (Allow for minor variations due to uncertainties of measurement.)
 * 2) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">List the 6 types of collisions (top of page 312) and a brief description.
 * 3) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Which types of collisions are definitely inelastic? How do you know?
 * 4) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Which types of collisions are definitely elastic? How do you know?
 * 5) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Define the law of conservation of momentum.
 * 6) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Use the law of conservation of momentum to describe what happens when a cue ball hits the 15 balls in the middle of the pool table.

Answers

1) The initial momenta is almost identical to the final momentum in each trial. Most are off by a couple of decimals. 2) The 6 types of collisions are the following: A moving object hits a stationary object: both stick together and move together with the same velocity. Two stationary objects explode by the release of a spring between them and move off in opposing directions. A moving object hits a stationary object: the initially moving object comes to rest, and the object originally at rest moves off in the same velocity as the first object A moving object hits a stationary object, and both move off at different speeds Two moving objects collide: both objects move at different speeds after hitting each other. Two moving objects stay together: move together at the same velocity 3) Collision types 1 and 6 are probably inelastic. Inelastic Collisions happen when the carts stick together, thus they do not bounce off. We did this in our lab with the use of velcro. 4) Collision types 2,4, and 5 are probably elastic. Elastic collisions happen when the carts bounce off of each, thus they do not stick together. 5) The total momentum is equal to the total momentum after the collision if there are no outside forces acting upon. 6) The momentum of the balls after the collision, as well as, the momentum of the original cue ball are equal. The natural forces are conserving the momentum. The momentum will stay the same.


 * Conclusion:**
 * · Based on the law of conservation of momentum, how can the traffic-accident investigators use to "reconstruct" the accident? What does it mean to "conserve" momentum?
 * Investigators should realize both the mass and the momentum of vehicles. This could let the investigators find out the masses and momentum before and after the collision. The idea of conserving momentum simply means to maintain the same momentum throughout.
 * · Explain at least 1 cause of experimental error. Be sure you describe a specific reason.
 * The track was at level throughout all the trials due to the fact that the motion sensor was under the ramp. Also, the motion sensor could have been on a little bit of an angle, which would throw off some results. Sometimes the wheels did not roll correctly, as well.
 * · How would you improve the results of this lab? (In other words, what would you change about the materials or procedure to eliminate or reduce the experimental error you describe above?)
 * I would make sure that the ramp is perfectly flat and that the motion sensor is lined up with the motion cart.