7. a box is pulled straight across the floor at a constant speed. it is pulled with a horizontal force of 48 n.
a. find the net force (in n) on the box.
b. find the force of friction (in n) from the floor on the box.
c. the person pulling on the box stops pulling and the box comes to a rest. find the force of friction (in n) on the box when at rest.

a)Taking into consideration Newton’s second law, we know that

Net_Force = mass * acceleration

Since the box is pulled at constant speed, the acceleration is equal to zero.

This means that

Net_Force  = 0 N

b) Force of friction

The net force is equal to the sum of all forces,

Net_Force   = Force_applied - Friction

We found that Net_Force  = 0, which means

Friction = Force_applied = 48 N

c)If the box comes to a stop. And the applied force becomes zero, the friction force becomes also zero.

Friction  = 0 N

the focus of lesson 1 is newton's first law of motion - sometimes referred to as the law of inertia. newton's first law of motion is often stated as. an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

explanation:

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.