Which of these represents a scenario where gravitational potential energy increases? a. A hockey puck is hit across the ice b. A rock falls from a cliff c. An elevator goes from the 4 th floor to the 10 th floor d. A bucket of water at the top of a building is poured out

It's a snowy day and you're pulling a friend along a level road on a sled. you've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. you've been walking at a steady 1.5m/s, and the rope pulls up on the sled at a 32 ∘ angle. you estimate that the mass of the sled, with your friend on it, is 65 kg and that you're pulling with a force of 80 n .