A 2 kg ball moving straight down strikes the floor at 8 m/s. It rebounds upward at 6 m/s. What is the magnitude of the change in momentum of the ball?
A 2 kg ball moving straight down strikes the floor at 8 m/s. It rebounds upward at 6 m/s. What is the magnitude of the change in momentum of the ball?
The change in magnitude of the ball is 28 kgm/s.
Solution:
Here,
mass of the ball (m) = 2kg
initial velocity of the ball (u) = 8 m/s (say downward direction is positive)
final velocity of the ball (v) = -6 m/s (because in upward direction)
Hence,
change in linear momentum of the ball (delta P) = m(v-u)
= 2 (-6 - 8)
= 2 (-14)
= -28 kgm/s
The magnitude of change in linear momentum of the ball is 28 kgm/s.