A block of mass
m = 5.0 kg
is pulled along a rough horizontal surface by a rope as sketched in the figure below. ( rope is at a 30 degree angle from the horizontal) The tension in the rope is 50 N, and the coefficient of kinetic friction between the block and the surface is
μK = 0.35.
(a) If the block travels a distance of 6.0 m along the surface, what is the work done by the rope?
259.8J
(b) Find the work done by friction on the block.
I tried to use Workk= coefficient of friction x mass x g x displacement
= .35(5kg) (9.8) (6m)= 102.9 and then negative because it is in the opposite direction of the work done by the rope. but this is not correct.
Then I tried the same formula and added cos(angle)
Workk= - (coefficient of friction) (mass) (g) (displacement) (cos(angle))
=(.35) (5) (9.8) (6) (cos 150)
= -89.1
I am not sure what else to try.
1 answer
1 answer