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(I am given a diagram; I'll attempt to describe it here.)

Consider a frictionless, 12000-kg roller coaster that starts at rest at the top of a hill, point A, 95 m high. It goes all the way down the hill and coasts horizontally (for an unspecified distance) before reaching point B (0m high) .

Calculate:

a) The force that must be applied to bring it to a stop at point B

b) The work done to bring it to a stop at point B

My answers:

a) Now, I usually don't post a question without SOME attempt at an answer, but I'm really stumped here. If I can determine the magnitude of the force of the roller coaster at B, it's simply that magnitude in the opposite direction. However, I can't because F = ma, and I can't find the acceleration because it's an expression of change in velocity over time, and I can't figure out the time because no distance is given! *head explodes*

Please, somebody start me off on the right foot here!

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# Roller coaster K/P energy problem wheeeee!

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