Work and Energy

In this lab, we were going to study about work and energy.

we went out side to calculate the amount of work for walking up in height h with stair and how much work we use to drag an object up the same height. We will also calculate the power as well.

We had three steps we need to do in lab.

1.drag a bag with mass of 9 kg and record the time we used.

2.walk up to the same height and record the time we used.

3.run up to the same height and record the time we used.

From the equation, we can calculate the work to apply to finish our work.

W=Fd

First,we need to know the height of the floor.

we measure each stair height is 0.17m, and there are 26 steps, so the total height is 4.42m.

And then, we measured the time for dragging object, walking, and running.

dragging: 15.45s

walking: 16.13s

running: 4.77s

dragging:

Work:

(9kg) (9.8m/s^2)(4.42m) = 389.844 joules

Power:

work / 15.45 second = 25.23 watts

walking:

Bag on pulley:

(95kg)(9.8m/s^2)(4.42m) =  4115.02 joules

Power:

work / 16.13 seconds = 255.11 watts

running:

Bag on pulley:

(95kg)(9.8m/s^2)(4.42m) =  4115.02 joules

Power:

work / 4.77 seconds = 862.68 watts