coefficient of kinetic friction?

Question

A box slides down a 34° ramp with an acceleration of 1.16 m/s2. Determine the coefficient of kinetic friction between the box and the ramp.

i already did the free body diagram and i know i have to find the magnitude using geometry but i don't know how to do it.

Answer 1

m*g*sin(34) is the force that gravity pulls downward on the object; m*g*cos(34)*u is the force of friction working against the sliding. mg[sin(34)-cos(34)U]=m*1.16
Therefore, 1.16/9.8=[.559-.829U']
.118-.559=.829u
.440=.829u
u=.531