Question

A 3−kg box rests on a horizontal surface. The coefficient of kinetic friction between the box and surface is μK=0.8. A horizontal force pulls the box at constant velocity for 13 cm. Assume the positive x-axis is the direction of motion. Find the work done by

a. the applied horizontal force,
b. the frictional force,
c. the net force. Answer:

Answer 1

The work done by the applied horizontal force is zero, the work done by the frictional force can be calculated using the formula frictional force = coefficient of kinetic friction x normal force, and the net force is zero.

Step-by-step explanation:

To find the work done by the applied horizontal force, we can use the formula:

Work = force x distance

Since the box is moving at constant velocity, the applied horizontal force is equal in magnitude and opposite in direction to the frictional force. Therefore, the work done by the applied horizontal force is zero.

The frictional force can be calculated using the formula:

Frictional force = coefficient of kinetic friction x normal force

The normal force is equal to the weight of the box, which can be calculated as:

Normal force = mass x gravitational acceleration

The net force is the vector sum of the applied force and the frictional force. Since the box is moving at constant velocity, the net force is zero. Therefore, the work done by the net force is also zero.