Question

A 25 N block is lowered 1.2 m by a 20 N force.

a. Draw a free-body diagram of the forces acting on the block.
b. How much work does the force of gravity do on the box? Is this work positive or negative?
c. How much work does the applied force do on the box? Is this work positive or negative?

Answer 1

a. The free-body diagram for the block consists of three forces: the gravitational force (weight), the normal force, and the applied force. b. The work done by the force of gravity is positive and can be calculated using the formula work = force × distance. c. The work done by the applied force is negative and can also be calculated using the formula work = force × distance.

Step-by-step explanation:

a. The free-body diagram for the block consists of three forces: the gravitational force (weight) acting downward, the normal force acting upward, and the applied force acting downward.

b. The work done by the force of gravity on the box can be calculated using the formula work = force × distance. In this case, the force of gravity is equal to the weight of the block and the distance is the vertical height through which the block is lowered. So, the work done by gravity = weight × distance = 25 N × 1.2 m.

c. The work done by the applied force can also be calculated using the formula work = force × distance. In this case, the force is equal to the applied force and the distance is the vertical height through which the block is lowered. So, the work done by the applied force = applied force × distance = 20 N × 1.2 m.