What is the life span and final outcome of low, medium and massive size of stars?

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

How does the kinetic energy of a charge change as the charge moves under the effect of an electric field from higher potential to lower potential? a. the kinetic energy increases. b.the kinetic energy decreases. c.the kinetic energy remains the same. d.the kinetic energy is always zero.

What was the first instrument to ever record an earthquake?