A 250-N force is directed horizontally as shown to push a 29-kg box up an inclined plane at a constant speed

Question

i need to know magnitude and coffiecent of kinetic friciton

Answer 1

I'll make some assumptions since there is no diagram:

First, the angle of incline subtended by the horizontal plane and the incline is th, an unknown angle

The 250-N force is applied in the horizontal plane.

Consider a FBD of the box.

The forces parallel to the plane are (with positive up the slope):

gravity
-sin(th)*m*g
and the parallel component of the force
cos(th)*250
-f
where f is friction
I will use 10 m/s for g
cos(th)*250
-sin(th)*290
-f=0 since the speed is constant

f is the normal force, N, times u the coefficient of kinetic friction

N=cos(th)*290-sin(th)*250
f=N*u

do some algebra and find that
(cos(th)*250
-sin(th)*290)/
cos(th)*290-sin(th)*250
=u

j