A 15.0 kg box is allowed to slide from rest down a ramp that makes an angle of 30.0^o to the horizontal. The coefficient of friction between the box and the ramp is 0.400 and the ramp is 5.00 m long. All calculations must be done using work and energy concepts. A. Calculate the work done by the force of gravity on the box from the top of the ramp until it gets to the bottom. B. Determine the work done by friction from the top of the ramp until the box gets to the bottom. C. Calculate the final velocity of the box at the bottom of the ramp. A 2.00 kg cannon ball is shot horizontally from the edge of a castle wall that is 10.0 m above the ground. The initial velocity of the cannon ball was 30.0 m/s. A. Calculate the initial total mechanical energy of the ball using the ground as the reference point for potential energy considerations. B. Calculate the velocity of the ball when it strikes the ground using energy considerations. C. Can you determine the direction of the final velocity using energy considerations? Why are why not? Please help me