4.1 Video Motion Analysis using “Tracker”

*Graphs of the first video*

4.2 Data Analysis

- Which wheels are you drive wheels? (front or back)

The back wheel, which is the bigger wheel on the car

- What is the circumference of your drive wheels?

The circumference is 37.7cm

- How far will your car travel in one rotation of the drive wheels?

37.7cm

- How many rotations (on average ) were there in each run?

18.6 rotation

- How much string is used in one rotation of the drive wheels? Show how you calculated this.

string length : 43.8cm

string used for one rotation : 43.8 / 18.6 =2.35cm (2 d.p.)

string used for one rotation : 43.8 / 18.6 =2.35cm (2 d.p.)

- The release of the lever is the power stroke. What is the length of your vehicles power stroke? (Length of string released)

23.5cm

- Calculate how far your vehicle will travel during the power stroke. Show your calculations!!

length of string release: 23.5cm

string used for one rotation: 2.35

total rotation: 23.5/2.35 = 10

ans: 10cm

string used for one rotation: 2.35

total rotation: 23.5/2.35 = 10

ans: 10cm

- Compare the answer to #7 to the distance your measured during your car’s power stroke. Discuss possible reasons for different valuables.

because we rounded our answers and our answers are taken from the average, the results might be different.

- Calculate the average velocity for your car during the period after the spring fully releases.

5m/s

- What force causes your car to stop?

friction causes the car to stop

- The work done by a force is calculated by multiplying the force times the distance over which it acts. The work done on an object is equal to the change in its kinetic energy. Can you find a way to calculate the force of friction? Use equations and explain your steps. HINT: Be careful, you have calculated average velocity. How can you find the total amount of kinetic energy (immediately after spring release) if we assume the acceleration during coasting was constant?

KE= ½ x 0.344kg x 5^2

=4.3J

- Various experiments have been done to measure the potential energy available from the spring. One estimate is 0.65 Joules. Using your estimates of the maximum kinetic energy of your car and the work done by friction, discuss whether or not this is a reasonable value. Can you account for any differences in the forms of energy? You must justify all of your arguments

½ x 0.344kg x (v)2=0.65

Thus, v=3.78m/s

½ x m x (5)2=0.65

Thus, m=0.052

I do not think that this is a reasonable value as energy cannot be destroy or created but can only be converted from one form to another and from the previous question, we calculated that the kinetic energy of the car was 4.3J and we feel that the the stored energy that will be changed from elastic potential energy from the string to other forms does not give a value any closer to 0.65J

I do not think that this is a reasonable value as energy cannot be destroy or created but can only be converted from one form to another and from the previous question, we calculated that the kinetic energy of the car was 4.3J and we feel that the the stored energy that will be changed from elastic potential energy from the string to other forms does not give a value any closer to 0.65J

## No comments:

## Post a Comment