A2.0-kg object is lifted vertically through 3.00 m by a 150-n force. how much work is done on the object by gravity during this process?

-58.8 J

Explanation:

The work done by a force is given by:

where

F is the magnitude of the force

d is the displacement of the object

is the angle between the direction of the force and the displacement.

In this problem, we are asked to find the work done by gravity, so we must calculate the magnitude of the force of gravity first, which is equal to the weight of the object:

The displacement of the object is d = 3.00 m, while , because the displacement is upward, while the force of gravity is downward; therefore, the work done by gravity is

And the work done is negative, because it is done against the motion of the object.