A box is sitting on a table. The mass of the box is 5.2 kg. The gravitational acceleration constant of Earth is approximately 10 m/s². What is the force that the table is exerting on the box to keep the box from accelerating towards the ground?

Question

Quizplus · Accepted Answer

The formula to find the required force is force = mass in kg × acceleration in m/s². 
F=ma
F = 5.2 kg x 10 m/s2
F = 52 N
The box experiences a force of 52 N from gravity and this force is down. Because of Newton's Third Law (The mutual forces of action and reaction between two bodies are equal, opposite and collinear), the table is pushing the box back up with the same force of 52 N upward. This is why the box does not crash to the floor. If the box was heavier and the table was not able to push upwards with the force required, the table would break and the box would crash to the floor.

A Box Is Sitting on a Table