An 8-kg ball rolling at 2m/s bumps into a pillow and stops in 0.5s (a) Show that the force exerted by the pillow is 32N. (b) How much force does the ball exert on the pillow?
Two people who weigh the same climb a flight of stairs. The first person climbs thestairs in 30s, while the second person climbs them in 40s. Which does more work? Which uses more power?