Question

A crate is lifted vertically 1.5 m and then held at rest. The crate has weight 100 N (i.e., it is supported by an upward force of 100 N). How much work was done in lifting the crate from the ground to its final position?
1. 150 J2. No work was done.3. None of these4. More than 150 J5. A bit less than 150 J

Answer 1

Answer:

1) W = 150 J

Explanation:

Work (W) is defined as the product of force F by the distance (d)the body travels due to this force.  

W= F*d Formula ( 1)

The work is positive (W+) if the force has the same direction of movement of the object.  

The work is negative (W-) if the force has the opposite direction of the movement of the object.

The component of the force that performs work must be parallel to the displacement.  

Work done to lift the floor box to its final position

We apply the formula (1)

W= F*d

W = (100 N)*(1.5 m)

W = 150 J