Which describes the average velocity of a unicycle going around in circles? check all that apply!

a. the total displacement divided by the time.

b. every time the unicycle returns to its starting point, the average velocity equals zero.

c. the slope of the acceleration vs. time graph.

d. the average acceleration divided by the time.

May someone explain how to do this question?

Which of the following elements is in the same period as phosphorus? a. carbon c. nitrogen b. magnesium d. oxygen select the best answer from the choices provided a b c d

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?