Finding F required pushing a box at angle (theta) for constant v

[Eats Dirt]

Homework Statement

a crate with mass m rests on a horizontal floor. a woman pushes down at an angle of theta below the horizontalon the frace with a force F, the coefficient of kinetic friction is Uk.
a) what magnitude of force F is required to keep the crate moving at a constant velocity?

Homework Equations

Ff(frictional force)=UkFn

Constant velocity which means Fnet=0

The Attempt at a Solution

since Fnet is 0 you can set horizontal force = to frictional force

Ff=Fsin(theta)
Uk(mg + Fcos(theta))=Fsin(theta)
(Uk(mg+ Fcos(theta))/sin theta = F

This is apparently not right and i can't thing of what else to do -_- help would be very much appreciated as well as an easier way of approaching problems with only symbols.
thanks!

 

[DukeLuke]

You are very close, but I think you mixed up the components of F. I think your cos and sin should be switched.