Question

A 35-N bucket of water is lifted vertically 3.0 m and then returned to its original position. How much work did gravity do on the bucket during this process?

Answer 1

Answer:

0 J

Explanation:

From the question, let us assume that a positive work was done in lifting the bucket down and a negative work was done in lifting the bucket up.

Going up

W = -Fd.................... Equation 1

Where W = work done,  F = Force needed to lift the bucket, d = distance

Given: F = 35 N, d = 3.0 m

Substitute into equation 1

F = -35(3.0)

F = -105 N.

Coming Down

W = Fd

Given: F = 35 N, d = 3.0 m

W = 35(3.0)

W = 105 N.

During the process (going up and coming down)

ΔW = -150+105

ΔW = 0 J

Hence the work done  by gravity during the process = 0 J

Answer 2

Answer:

W = 105 J

Explanation:

Given:  F= 35 N, D= 3.0 m

W=?

Sol:

Work done = Force × distance

W = 35 N × 3 = 105 J