Physics with Kinetic Enegry?

Question

A 974 N crate is pushed across level floor with 318 N at an angle of 23 degrees above the horizontal. kinetic friction is .25. acc. of gravity is 9.81. What is the acceleration of the box? I'm blank

Answer 1

Construct a free-body diagram on the box. The forces are:

mg, down
N, up
μN, back
P, angle of 23 above horizontal

There's no vertical acceleration so the net vertical force is zero:

F = ma = 0 = N - mg - P sin 23

Solve this for N.

Now for the horizontal motion:

F = ma = P cos 23 - μ N

Plug in the N you found above and solve for the acceleration a.