A block of mass "m" is pulled across a rough table by a string at an angle "θ" above the horizontal at a constant velocity. What is an equation for the magnitude of the kinetic friction force, fk?
The answer that I was given was μk(mg-T*cos(θ))
mg*cos(theta)=magnitude of force in x direction[/B]
The Attempt at a Solution
I just thought it would be mg*cos(theta)=uk*Fn
Since there is no acceleration, the frictional force in the positive x direction must equal the force in the negative x direction...so, T*cos(theta), which is the same in this situation as uk*Fn.
Why that weird answer? Anybody?