A roller coaster has a mass of 275 kg. It sits at the top of a hill with height 85 m. If it drops from this hill, how fast is it going when it reaches the bottom?
Answer 41xm/s Explanation: The potential energy of the roller coaster is converted into kinetic energy when it reaches the bottom. So we can write: m g h = 1 2 m v 2 ∴ v = √ 2 g h v = √2 x 9.8 x 85 = 41 m/s As you can see, the mass given is irrelevant to the question.
