Question

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.

Answer 1

Comparing kinetic energy of Boat A and B -Option 4

Compared to the kinetic energy of Boat B, the kinetic energy of Boat A is nine times as much. Kinetic energy ( K.E ) is the energy which is possessed due to movement or motion. Its formula is 1 / 2 mv 2, there is square of velocity in terms of kinetic energy.

If the velocity of boat A is three times greater than that of boat B and the condition is both boats have the same mass so by putting values. Mass is constant and the square of velocity is ( 3 ) 2 = 9 therefore, 1 / 2 m ( 3v ) 2 = 1 / 2 m 9 v 2.

If we write it as 9 ( 1 / 2 m v 2 ) it means that kinetic energy of boat A is nine time as much.          

Answer 2

D. Nine times as much.