Physics Help? C4:2

Question

A horizontal 100-N force is applied to a 20-kg box that is initially at rest on the floor.  The coefficient of static friction between the box and the floor is 0.40, and the coefficient of kinetic friction between the box and the floor is 0.35.

 

2)         What is the magnitude of the force exerted by the ground on the box?

Answer 1

Step 1:

The coefficient of static friction is 0.40.

The coefficient of kinetic friction is 0.35.

Horizontal force is 100 N.

Mass of the box is 20.0 kg.

Force due to kinetic friction .

Normal Force , then

.

Maximum frictional force offered by the block is .

Net force .

Net force of the block is 100 N.

As the total force acting on the block is less than the maximum value of Frictional force, the applied is cancelled out by an equal and opposite force and the block remains at rest.

Solution:

Net force of the block is 100 N.

The block remains a rest.