Exciting Physics Problem: Normal Force Calculation!

What must be the normal force of the floor acting on the box?

If an object weighs 20 N and is sitting on the floor without moving, what must be the normal force of the floor acting on the box?

A. 20 N up

B. 20 N down

C. 10 N up

D. 10 N down

Answer:

20 N up

When an object weighs 20 N and is sitting still on the floor, the normal force of the floor acting on the box must be 20 N up. This is based on Newton's law of force, which states that for objects at rest, the forces acting in opposite directions must be equal to maintain the equilibrium.

In this scenario, the object exerts a downward force of 20 N due to its weight. In response, the floor exerts an equal and opposite force of 20 N upwards, known as the normal force. This balancing act of forces ensures that the object remains stationary and does not move.

Therefore, the normal force of the floor acting on the box in this case is 20 N upwards, keeping the object in place and preventing it from accelerating.