thom+ch3

'Maurel Thom's Wikilog - Period 6 CP Physics - Burns - 2011

Chapter 3

SECTION 1 What Do You See I see a crash test. The driver is being pushed into the airbag. There is a teddy bear that was flying through the air that was probably in the back seat - it was launched forward. The front of the car is being compressed into the wall.

What Do You Think The safest thing to do in a crash might be the fetal position.(?) Putting your head between your knees.

Investigate Step 1:

Step 2: Assistant Analyst a) I wasn't really surprised. Some of the statistics and feedback were interesting though.

Step 3:

(yes/no) || New Cars (1,2,3) ||
 * ** Safety features ** || Means of protection || Pre-1960 cars
 * seat belts || Prevents forward motion || n || 1, all ||
 * head restraints || Protects from whiplash || n || 1, all ||
 * front airbags || Protects from steering wheel || n || 1, all (drivers side) ||
 * back up sensing system || Prevents backing into objects || n || 3, few ||
 * front crumple zones || Increases momentum stop time || n || 1, 2, all, some ||
 * rear crumple zones || Increases rear end stop time || n || 2, some ||
 * side-impact beams in doors || protects from side collisions || n || 2, some ||
 * shoulder belts for all seats || prevents body from leaving seat || n || 1, all ||
 * anti-lock braking systems (ABS) || reduces stop distance || n || 2, some ||
 * tempered shatterproof glass || glass wont shatter - cause injury || y || 1, all ||
 * side airbags || reduces side impact || n || 2, some ||
 * turn signals || alerts drivers and pedestrians || y || 1, all ||
 * electronic stability control ||  || n || 2, 3, some, few ||
 * energy-absorbing collapsible steering column ||  || n || 1, all ||

Physics Talk People in vehicles are not the only ones in danger, pedestrians are also at risk. In 1965, Ralph Nader wrote a book that highlighted the problems with vehicles. Since then, car manufacturers have improved the safety.

Physics to Go

What Do You Think Now You can't react yourself fast enough to protect yourself DURING an accident, but prior to, you can take preventative measures. Wearing your seat belt and obeying the speed limit are key things.

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 seat belt?
 * Alot depends on speed, but in general, a passenger without a seat belt would go flying through the windshield, reducing their chance of survival in an accident. A passenger with a seat belt will most likely be kept in his seat, lurched forward into the airbag, and then go back against the seat and headrest - reducing the chance of injury in a collision.
 * What factors affect the passenger’s safety after a collision?
 * Hazard lights, windows/windshield, head rest, etc.
 * How would a seat belt for a race car be different from one available on a regular car?
 * A race car seat belt would be more efficient. It would be more like a vest (or like the straps on a bookbag) than a belt across your chest. The additional protection is required because race car drivers drive at higher and more dangerous speeds.

(in bullets)
 * 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).


 * 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: _ m


 * **//Type of Seatbelt//** || //**Before Picture**// || //**After Picture**// || //**Description and Observations**// || //**Group**// ||
 * Thread ||  ||   ||   ||   ||
 * Wire ||  ||   ||   ||   ||
 * String ||  ||   ||   ||   ||
 * Yarn ||  ||   ||   ||   ||
 * Ribbon ||  ||   ||   ||   ||
 * Rubber Bands ||  ||   ||   ||   ||

//** *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) What parts of your passenger were in greatest danger (most damaged)?
 * 4) What does Newton’s first law have to do with this?
 * 5) What materials were most effective as seatbelts? Why?
 * 6) Use Newton's first law of motion to describe the three collisions.
 * 7) Why does a broad band of material work better as a seatbelt than a narrow wire?

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. · Explain at least 1 cause of experimental error. Be sure you describe a specific reason. · 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?)

1296577690

**Investigate X3: Energy and Air Bags**

 * Objective:**
 * How does an air bag protect you during an accident?


 * 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).


 * 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 fully intact ||  ||
 * **Egg #** || **Drop Height** || **Cracked or Smashed?** || **Description and Observations** ||  ||
 * 1 || 2 ||
 * 1 || 4 || cracked || minor crack in bottom ||  ||
 * 1 || 6 || cracked || crack became slightly larger ||  ||
 * 1 || 8 || cracked || crack larger ||  ||
 * 1 || 10 || cracked || crack larger ||  ||
 * 1 || 12 || cracked || crack larger ||  ||
 * 1 || 14 || cracked || crack larger ||  ||
 * 1 || 16 || cracked || crack larger ||  ||
 * 1 || 18 || cracked || yolk now visible ||  ||
 * 1 || 20 || cracked || yolk oozing out ||  ||
 * 1 || 22 || smashed || yolk was out of egg ||  ||
 * 2 || 22 || no || perfect ||  ||
 * 2 || 26 || no || perfect ||  ||
 * 2 || 30 || no || perfect || b ||
 * 2 || 34 || no || perfect ||  ||
 * 2 || 42 || no || perfect ||  ||
 * 2 || 50 || no || perfect ||  ||
 * 2 || 58 || no || perfect ||  ||
 * 2 || 66 || no || perfect ||  ||
 * 2 || 110 || no || perfect ||  ||
 * 2 || 265 || no || perfect ||  ||


 * Calculations:** Show equation(s), numbers plugged in, and answer with correct units. Add columns in your data table to include these results.
 * What is the gravitational potential energy in each trial?
 * How much work is done in each trial?
 * How much force was used to stop the egg in each case of steps 5, 8 and 9.

** *Read the Physics Talk p279 - 287 before answering the following questions. * **
 * Questions:**
 * 1) 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) Define the terms: Kinetic Energy and Work.
 * 3) What factors determine an object's kinetic energy?
 * 4) WHen work is done on an object, what is the effect on the object's kinetic energy?
 * 5) How does the force needed to stop a moving object depend on the distance the force acts?
 * 6) What difference does a soft landing area make on a passenger during a collision?
 * 7) How does a cushion reduce the force needed to stop a passenger?
 * 8) What does the law of conservation of energy have to do with this?

· 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. · Explain at least 1 cause of experimental error. Be sure you describe a specific reason. · 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?)
 * Conclusion:**

USE THE RUBRIC TO MAKE SURE YOU HAVE INCLUDED ALL REQUIREMENTS!

USE THE RUBRIC TO MAKE SURE YOU HAVE INCLUDED ALL REQUIREMENTS!

SECTION 6