What Is the Coefficient of Kinetic Friction on a 40 Degree Incline?

[traffic_boy]

Homework Statement

a block of unknown mass is given a push up a 40 degrees inclined plane and then released.
it continues to move up the plane (+) at an acceleration of -9m/s squared.what is the coefficient of kinetic friction ?

Homework Equations

f(friction) + mg cos 50 - F = -9 (m)
n = mg sin 50
f( kinetic friction)= (kinetic friction constant) .normal force (n)

The Attempt at a Solution

i have used the above mentioned equations but i couldn't find the right answer..
sooo,, am looking forward for any help guys...

 

[rl.bhat]

You have mentioned 40 degrees inclined plane. With respect to what? Because in the relevant equation you have used 50 degrees.
So, show your calculations. Identify all the forces acting on the block on the inclined plane.

 

[traffic_boy]

You have mentioned 40 degrees inclined plane. With respect to what? Because in the relevant equation you have used 50 degrees.
So, show your calculations. Identify all the forces acting on the block on the inclined plane.

thank u for replying,,well,i've mentioned the 40 degrees inclined plane, but the only benefit
of this 40 degrees is to help us to find the x component of weight, so if we complete the triangle made by the incline and the perpendicular line of the weight force , we'll get 50 degrees angle ...