Newton Car Lab Report

Science 1

Jonathan Chou

Purpose:

The purpose of this lab is to find if changing the mass of a “Newton Car”, by manipulating the weight of the film canister will have an effect on the acceleration and distance the car travels.

Hypothesis:

If we decrease the weight in the film canister, then the “Newton Car” will be able to travel farther because of the reduced amount of weight pressure on the car.

Materials:

-Film Canister

-Toilet Roll

-Rubber Band

-Wood Block

-3 screws

-matches or lighter

-String

-Rods

-eye protection

-beaker filled with water

-scissors

Procedure:

  1. Using a toilet roll as a guide, tie 8 strings loops of equal size. They should all be about 4cm in diameter (More than 6-10 loops of string may be needed for this investigation. Be Prepared)
  2. Fill up your film canister and weight it in grams. Initial Mass= 126.5g
  3. Set up your Newton Car as shown in the picture to the right.
  4. Slip the rubber band through the string loop.
  5. Stretch the rubber band over the two screws and pull the string back over the third screw. Use only one rubber band the first time.
  6. Place the rod 4-5 cm apart on the flat surface (You decided how far they are, but keep it consistent(
  7. Put on eye Protection
  8. Using a match, light the string from above and stand back. (Be extra cautious lighting the string. If you have long hair it must be tied back.) If the hand or fingers of the person lighting the car is hit by the car, then repeat so that this does not contribute any errors.
  9. Record the distance the car traveled in the table. (You decide whether you are recording from the back or front of the car- make sure you indicate this in you procedure.) You data table should have at least one column per trial plus a column for averages. You will be using the averages to create a bar graph.)
  10. Repeat steps 3-6 two more times for a total of three trials. Record all three of your trials.
  11. Manipulated the rods distance from each other to 10 cm
  12. Manipulated weight of canister (decreased it)
  13. Manipulated weight of canister (increased it)
  14. Manipulated rod distance to 3 cm
  15. Increased number of rubber bands to 2

Trial # / Manipulated variables / Distance
1 / none / 65 cm
2 / none / 69 cm
3 / none / 73 cm
4 / Rod Distance=10cm / 163 cm
5 / Canister Weight decreased =84.5 g / 155 cm
6 / Canister Weight = 153.6 g / 120 cm
7 / Rod Distance = 3 cm / 44 cm
8 / 2 rubber bands / 128 cm

Data and Observations:

Bar Graph (Separate sheet of paper)

Manipulate-able variables

-Rods distance from each other

-Number of rubber bands

-Weight of canister

-Amount of string (if possible)

Dependent variables:

-Distance that “Newton Car” travels

-Speed that “Newton Car” travels

-How fast the canister is forced backward

Controlled Variables

-Weight of wood block, number of wood blocks (1)

-Number of screws, weight of screws

Observations:

It took a while to strike the match and we had to be able to strike it swift and steadily so that the match wouldn’t break. It took a few seconds, sometimes only part of a second for the string to release the rubber band. Each trial took no more than 7-8 seconds. The canister was released with so much force that the “Newton Car” was released almost immediately. I thought that the lighter might have worked better than the matches since the lighter exerted a more powerful fire. Increasing the rod’s distance from each other and by decreasing the weight of the canister doubled the distance that our “Newton Car” could travel.

Conclusion and Analysis:

My hypothesis was right since the decreased weight of the canister had a positive effect on the distance the “Newton Car” could travel across the rods. My results show that the distance the “Newton Car” traveled was roughly 2.2xs farther than our best trial of the first three. Even though Newton’s third law suggests that for every action there is an equal and opposite reaction, weight pressure on the wood block is still at play. Even so, increasing the weight of the canister didn’t help as much as decreasing the weight of the canister. I learned that decreasing the rod distance had a negative effect on the distance the car could travel. Increasing the number of rubber bands on the other hand set off a stronger outward push having a positive effect. But, by conducting more tests by increasing the weight of the canister significantly could give me a better understanding on which manipulated variables would have a positive effect.

The experiment turned out the way it did because we were able to follow the lab procedure step by step. Specifically, we were able to strike the match successfully, cut a required string length to loop over the screw, settle the canister in the right place, etc. Our first three trials improved from 65 to 69 and to 73 cm, because each time we learned from the mistakes we made in the past trial. For example, once we placed the match on the string for a too short period of time, so it might have an effect on the forced of the string releasing the rubber band. The purpose of this experiment relates to the real world because it relates to Newton’s three laws. The releasing of the string upon the rubber band upon the string sending the “Newton Car” forward is a basic model for a rocket. This models Newton’s 3rd law that for every action there is an equal and opposite reaction and Newton’s 2nd law that force will cause a change in the motion of an object. The change in motion depends on the amount of force and the mass of the object. For example, when you hit another bumper car with your bumper car, you exert a force on that car. Even if you hit a car that is at rest, that car is also exerting a force on you. These forces are opposite, or moving in different directions from each other. Same thing goes with the “Newton Car.” As the canister is fired backwards, another force pushes the car forward.