A physics TA pushes a 20.0 kg equipment cart at a constant velocity for a distance of 20.0 m down the hall. The force she exerts on the cart is directed at an angle 27.0° below the horizontal, and the force of friction opposing the motion of the cart is 56.0 N. Determine the following.
a)the work done (in J) by the force the TA exerts on the cart
b)the work done (in J) by the force of friction acting on the cart
c)the work done (in J) by the force of gravity acting on the cart