Questions in attachments. please explain your answers.

Refer to the figure below. A block is pushed at constant speed up a ramp thru points A and B (that is, the block does not come to rest at either point). The hand exerts a horizontal force on the block (that is, the force is not parallel to the ramp). There is friction between the block and the ramp. The distance between points A and B is 1 m. 18. Compare the KB at B to the KB at A. 19. Find the total work done on the block as it travels from point A to point B. 20. Write an expression for the work done by the hand as the block travels from point A to point B. 21. A ball, starting from rest, slides down a frictionless incline and reaches a velocity of 12 m/s at the bottom. At what height did the ball start? A block of mass m slides at velocity v along a horizontal frictionless table. It then slides down an inclined frictionless ramp through a height h. It continues sliding along a rough horizontal oor before coming to rest on the oor. Assume h = 0 on the oor. 22. On the tabletop, the TME of the block IS ? 23. As the block slides down the ramp, what happens to its TME? 24 What is the PE of the block on the oor at the bottom of the ramp? 25. The block experiences friction as it slides over the rough horizontal oor, and TME is at the point where the block comes to rest. 26. An object of mass 40 kg, initially at rest, moves on a frictionless horizontal surface. The total work done on the object is 1000 J. Find the object's nal velocity. Two identical blocks, A and B, are released from rest at the same height, as shown in the figure above. Block A slides down a steeper ramp than block B. Both ramps are frictionless. The blocks reach the same nal height indicated by the lower dashed line labeled \"Finish\". 27. With regard to the work done on the two blocks by the gravitational force, which of the following is correct? A. Work is related to the product of force and displacement, and the weight is the same since the blocks are identical. But Block B travels further, so more work is done on Block B by the gravitational force than on Block A. Both blocks fall the same vertical distance, so the change in PE is the same. B. Both blocks fall the same vertical distance, so the work done is the same. C. By Newton's Third Law, the force exerted on the block by the Earth is exactly cancelled by the force exerted on the Earth by the block. The work done is zero. D. The work depends on the angle that the force makes with the displacement. If we put the displacement and force vectors tail-to-tail, the angle is smaller for Block B than for Block A, and so the work done is greater. 28. An ZOOkg boulder is at rest lOOOm above the ground. . What is its PE when it is lOOOm above the ground? What is its KE at IOOO-m above the ground? . The boulder begins to fall. What is its PE when it is SOD-m above the ground? . What is the KB of the boulder when it has fallen BOOm? What is the TME of the boulder at 100 m above ground? What is the speed of the boulder just before it hits the ground? mmunw> 29. A roller coaster car starts from rest at point A. What is its speed at point C if the track is frictionless? A 12.0 m 4.0 m 2.0 m 30. An 80.0 kg student running at 3.5 m/s grabs a rope that is hanging vertically. How high will the student swing