1-Oct.-14: Work-KE-Theorem

Purpose:
To verify the Work-Kinetic Energy theorem with a spring and cart apparatus.



Apparatus:
Our set-up required -
a rolling-cart with a wooden block, (m = 709-g)
a track for the cart,
a spring,
a position sensor, and
a force sensor.

 


The track provided a foundation for the entire experiment, as it was used to roll the cart on its surface.
We secured the force-sensor to the left end of the track using a clamp and a pole. We then attached a spring - one side to the secured force-sensor and the other side to the cart. At the right end of the track we placed a position sensor, which we programmed to take the origin of its measurements from the left end of the track.



Experiment:
To start, we set the left side of the track to be the origin (x = 0).
We pulled cart away from the force sensor (toward the right) and began collecting data as soon as the cart was released.
When the cart was released, it moved with some velocity toward the left and this velocity was captured through the motion detector.

After running the experiment and collecting data, we needed to analyze what had occurred.
We first recognized that the force sensor gave us a direct value for the force applied by the spring.

With this knowledge, we were able to create a Force-vs-Position graph, which gave us the work done by the spring when integrated over a certain interval.
We also added a calculated column for the Kinetic Energy at any given point using the known mass and the "velocity" variable from the motion detector.

We analyzed three separate sections of our graph by comparing the work done by the spring and the kinetic energy at three specific locations.

Our results:

1st -

Integral: 0.8197 N*m

Kinetic Energy: 0.636 J

2nd -

Integral: 1.203 N*m

Kinetic Energy: 1.164 J

3rd -

Integral: 1.556 N*m

Kinetic Energy: 1.331 J

Conclusion:

With slight uncertainty, we found that the work done on a cart by a spring is equal to the change in kinetic energy.

A Great Day for Physics.

(10/01/14 6:57 am)

29-Sep.-14: Work, Energy, and Power

Purpose:

To understand more about the concepts of energy by calculating the work and power done on a mass.

Apparatus:

Our set-up required -

a staircase, 4.42m

a balcony,

a one-way pulley,

a 5 kilogram backpack, and

a rope.

 

 

The staircase provided a way for us to measure the height from the ground to the floor of the balcony by measuring the height of one step and multiplying that value by the number of steps.

The balcony allowed us to secure the pulley a decent height above the ground so that we could do work on the 5kg mass using the rope while timing how long it would take to perform that amount of work using a stopwatch.

Experiment:

We began by measuring the height of one step on the stair case, which we agreed measured 17 centimeters - after counting 26 steps, the total height of the staircase was then calculated to be 4.42 meters.

Next, we measured 

1. The work it took for Michael, whose mass is 77-kg, to go up the 4.42-m staircase.
2. The power for Michael to walk up the stairs in 15.6 seconds.
3. The power for Michael to run up the stairs in 5.03 seconds.

Then, we measured the work and power of the backback - for this part we measured the same values of the backpack as we did with Michael.

1. The work done on the backpack through 4.42-m.
2. The power while raising the backpack in 3.5-sec.

A Great Day for Physics.

(9/17/14 6:56am)