The dimension of which of the following is the same as that of impulse?
(1) Volume
(2) Momentum
(3) Torque
(4) Change in the rate of momentum
Answer: (2) The quantity of impulse is force × time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.