A roller coaster is pulled up to the top of a hill 45 m high. The cart then moves over the crest at an average speed of 0.5 m/s before it plunges down to its lowest point, 5 m above the ground. From there, it climbs over a second hill only 15 m high. What is the cart’s speed as it goes over the top of the second hill?

On a horizontal frictionless surface, a small block with mass 0.200 kg has a collision with a block of mass 0.400 kg. immediately after the collision, the 0.200 kg block is moving at 12.0 m/s in the direction 30° north of east and the 0.400 kg block is moving at 11.2 m/s in the direction 53.1° south of east. use coordinates where the +x-axis is east and the +y-axis is north.(a) what is the total kinetic energy of the two blocks after the collision (in ) what is the x-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your ) what is the y-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your answer.)