Boat A and Boat B have the same mass. Boat A’s velocity is three times greater than that of Boat B. Compared to the kinetic energy of Boat B, the kinetic energy of Boat A is
one-third as much.
three times as much.
six times as much.
nine times as much.
since KE = 1/2 mv^2,
replacing v with 3v gives 1/2 m (3v)^2
so, 9 times as much