Two students are watching a person riding a skateboard up and down a ramp. Each student shares what they think about the energy of the skateboarder as they ride up and down the ramp. Elisa: I think the skateboarder has the more total energy at the top of the ramp than the bottom of the ramp. Raymond: I think the skateboarder has the same total energy at all points on the ramp. Which student do you agree with? Why?

Suppose while hauling rocks, you accidentally drop one. it breaks apart in flat, planar sections. what type of rock did you just drop? 20 points

Often called simply "velocity," this is the velocity of an object at a particular moment in time.

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.