Question -
Answer -
A ball rebounding between two walls locatedbetween at x = 0 and x = 2 cm; after every 2s, the ball receives an impulse of magnitude 0.08 × 10–2 kg m/sfrom the walls
The given graph shows that a body changesits direction of motion after every 2 s. Physically, this situation can bevisualized as a ball rebounding to and fro between two stationary wallssituated between positions x = 0 and x = 2cm. Since the slope of the x–t graph reverses afterevery 2 s, the ball collides with a wall after every 2 s. Therefore, ballreceives an impulse after every 2 s.
Mass of the ball, m = 0.04kg
The slope of the graph gives the velocity ofthe ball. Using the graph, we can calculate initial velocity (u) as:
.
Velocity of the ball before collision, u =10–2 m/s
Velocity of the ball after collision, v =–10–2 m/s
(Here,the negative sign arises as the ball reverses its direction of motion.)
Magnitudeof impulse = Change in momentum
=0.08 × 10–2 kg m/s