Question

A 10 kg box rests on the ground. What is the weight of the box? __ N

What is the normal force of the ground on the box? ___ N
The box is pushed to the left with 20 N of force, but does not move.
What is the Static Friction Force? ___ N
When the pushing force is increased to 40 N, the box just begins to move. What is the Maximum Static Friction Force? ____ N

Answer choices. 30 98 40. 9.8 98. 4.1 10 20. 2

Answer 1

The weight of an object is its mass times acceleration.

Weight of the box = (10kg)(9.81m/s^2) = 98.1N

If the box is at rest, then the normal force is equal to the weight of the box:

Normal force = 98.1N

If the box does not move, then the static friction force with 20 N is also 20N

Static Friction Force = 20N

If the box begins to move at 40, the maximum static friction force is equal to 40N

Maximum static friction force = 40N

Answer 2

Step-by-step explanation:

1. Mass of the box, m = 10 kg

Weight of an object is equal to the product of its mass and acceleration due to gravity. Its expression is given by :

W = mg

`W=10\ kg* 9.8\ m/s^2`

W = 98 N

2. The normal force acting on an object is equal to its weight. So, N = 98 N

3. If the box is pushed to the left with 20 N of force and it is not moving, then there is a force acting on it which is called frictional force. The static friction force have magnitude of 20 N and it is acting in opposite direction of motion.

4. When the pushing force is increased to 40 N and the box begins to move, then the maximum static frictional force is equal to applied force i.e. 40 N.