Explanation:
6a) Work = force × distance
W = Fd
W = (60 N) (10 m)
W = 600 J
6b) Change in energy = work
ΔKE = 600 J
7a) Kinetic energy is half the mass times the square of the velocity.
KE = ½ mv²
KE = ½ (0.4 kg) (25 m/s)²
KE = 125 J
7b) Work = change in energy. When the ball is stopped, it has zero kinetic energy.
W = ΔKE
W = 0 J − 125 J
W = -125 J
