10-April-2017: Lab 11: Physics 4A Work-Kinetic Energy Theorem Activity

 Lab 11: Physics 4A Work-Kinetic Energy Theorem Activity

Author: Tiancih Jiao

Lab Partner: Harvey Thai, Jesus Gonzalez

Purpose of the lab: Measure work done by forces and figure out how kinetic energy and the work-kinetic energy principle works in real life.

Theory/Introduction:

KE= 0.5* m * v^2

W = delta (KE) = KEf - KEi

In this experiment, we have 4 parts. The first is to hang a mass with a string to the force sensor on the cart. The second part is to use a spring to hang on the force senor, and pull the cart to 0.6 m position. The third part is when the cart pull to the 0.6 m position, release it and record the data. The last part is to watch a video and find the work done by the force.

Summary of apparatus/experimental procedure:

Summary of apparatus/experimental procedure:

1. Set up the track, cart, motion detector, force probe, pulley, cart stop and hanging mass.

Plug the force sensor, and zero it. Put a 500-g mass hanging on the force senor and calibrate it to 4.9 N.

measure the mass and put the mass in User Parameters.

Level the tract to reduce the errors.

hang a 50-g mass and release to get the graph.

2. Set up the ramp, cart, motion detector, force probe, and spring.

make sure spring is unstretched. move the cart slowly to 0.6 m position. Sketch the graph.

3.Move the cart to 0.6 m position, then release the cart and graph.

Find the change in KE of cart after release. then find the work.

4. When we have the distance and the time, we can calculate the final speed and the KE of the cart.

Measured data:

M cart = 500 g

User parameters : m = 1 kg

For the first graph, we get the integral is 0.1788, and the KE is 0.160, which is very close to each other.

And then we change the area larger, we get integral is 0.3002, and the KE is 0.277.

For the next part, we get integral is 0.02471, and the KE is 0.023.

So we get that the area of the force graph is close to the KE calculated by the KE  equation.

Conclusion:

From the result of the experiment, we can get that the integral of force is pretty close to the KE. The level and the mass measure would be the error of this experiment.