If a disk rolls smoothly across a floor, what is the velocity of the point that is in contact with the floor? a. twice the velocity of the center of the disk
b. equal to the velocity of the center of the disk
c. zero

Why is the energy that results from a roller coaster's position at the top of a hill referred to as potential energy?

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e

Which of the following are used in an electrochemical cell? a. electrodes b. electrolyte c. terminals d. all of the above