A Physics Question

Question

Len pushes toward the right on a 12.0 kg box with a force of magnitude 31.0 N. Martina applies a 11.0 N force on the box in the opposite direction. The magnitude of the kinetic friction force between the box and the very smooth floor is 4.50 N as the box slides toward the right. What is the box’s acceleration?

Answer 1

A free body diagram might look like:

ΣF_x = 31.0 - 11.0 - 4.5 = 15.5 N (to the right)

F = ma

a = F/m

a = 15.5/12.0 = 1.3 m/s² (to the right)