Two rectangular boxes are stacked vertically in an elevator. The one on the bottom has a mass of 5.00 kg and the one on the top has a mass of 2.00 kg. The elevator, the UPS person, and both boxes are accelerating upward at 2.50 m/s^2. What is the magnitude of the normal force between the two boxes?

Question

Two rectangular boxes are stacked vertically in an elevator. The one on the bottom has a mass of 5.00 kg and the one on the top has a mass of 2.00 kg. The elevator, the UPS person, and both boxes are accelerating upward at 2.50 m/s^2. What is the magnitude of the normal force between the two boxes?

I got 37.1N but I'm not confident in that answer.

Are the normal forces of top onto bottom and bottom onto top the same?

Please help. Thanks

Answer 1

the top box is being accelerated at 2.50 m/s^2 against the force of gravity

... what is causing the acceleration?

the accelerating force equals the weight (m * g) of the top box
... plus the force from the elevator acceleration

2.00 kg * (g + 2.50 m/s^2)