A 100 N force directed 37° below the horizontal is applied to a 30 kg object on a horizontal surface. If the magnitude of the acceleration of the object is 1.3 m/s2, what is the coefficient of kinetic friction (μk) between the object and the surface?
2. Relevant equations
F = ma
3. The attempt at a solution
I drew the body diagram and tried calculating the net force in the x direction.
This is what I got:
F = Fpx (the 100 N force) – Ffr
Fpx is 100cos37 and Ffr is μmg, so
ma = 79.86 – 294μ
I plugged in 1.3 for a and got 0.24 for the answer.
The correct answer is 0.12.
Not sure where I went wrong, any help would be appreciated. Thanks!