A 25 kg box is pulled across a wooden floor...

Question

A 25 kg box is pulled across a wooden floor with a rope. The rope makes an angle of 30o with the floor. The coefficient of friction between the box and floor is 0.21. A force of 75 N is exerted on the rope. How fast does the box accelerate along the floor?

Answer 1

This is almost identical to the other acceleration problem.

 

F_h = 75cos30 = 65 N

F_v = 75sin30 = 37.5 N

 

N = 25(9.81) - 37.5 = 207.75 N

F_f = .21(207.75) = 43.6 N

 

F = F_h - F_f = 65 - 43.6 = 21.4 N

 

a = F/m = 21.4/25 = .856 m/s²