A ball is thrown straight upward from the ground with an initial speed of ; upward is…
PHYSICS · Single correct · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A ball is thrown straight upward from the ground with an initial speed of +10m/s; upward is defined as the +y direction. Just before the ball returns to the thrower’s hand, which of the following best describes the sign of the ball’s linear momentum?
(a) Positive, because linear momentum is conserved and equals the initial upward momentum.
(b) Zero, because the ball momentarily comes to rest at the top of its path.
(c) Negative, because the ball’s velocity is downward just before it reaches the thrower’s hand.
(d) Positive, because the ball finishes where it started, so its momentum must have the same sign as initially.