PHYSICS · Multi-part · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A light plastic puck slides on a horizontal, perfectly smooth ice rink. While its speed remains constant at v, it is deflected through 45∘ by a gentle bump on the side boards. Assume no other external forces act on the puck during the short contact interval.
(i) Define linear momentum and state its SI unit.
(ii) The puck’s speed before and after striking the boards is the same. Does its momentum change? Give reasons based only on the physical meaning of momentum.
(iii) Draw a neatly labelled vector diagram showing the initial and final velocity vectors and explain how the change in momentum vector can be obtained from these two velocity vectors by geometrical construction.