Posted by Tia on .
you push with a 40N horizontal force on a 2kg box of coffee resting on a horizontal surface. The force of friction on the box is 12 N. Show that the acceleration is 4 m/s^2

Physics 
MathMate,
Net force after friction
= 40N  12N=28N
mass = 2kg
Use F=ma and solve for a (acceleration).
Note: not sure if the question is correct, either the mass=7kg or acceleration = 14 m/s².