Question

QUESTION 2 10 P A bullet of mass 30 g moving with a speed of 500 m/s strikes a block of wood of mass 2.0 kg and becomes imbedded in it (stuck inside it). The block had been originally at rest and is free to move. What is the speed of the block and bullet immediately after the collision? 2.5 m/s 9.4 m/s 14 m/s 7.4 m/s QUESTION 3 10 poi A tennis ball of mass 0.0600 kg is initially moving horizontally with a speed of 25.0 m/s. A tennis player hits it with his racket with an average force of 70 N, sending the ball back in the opposite direction with a speed of 35.0 m/s. For how much time was the racket and ball in contact, in units of seconds? QUESTION 4 10 point If a ball has a mass of 0.240 kg and a speed of 21.2 m/s, what is the magnitude of its momentum, in units of kg.m/s? 10 points

Answer 1

2) Conserving Momentum,

Initial momentum = mv = 30/ 1000 × 500 = 15 kgm/s

Final momentum = (2 + 0.03) v

Hence equating them, we have

2.03 v = 15

v = 7.39 m/s

The speed of the block and bullet is 7.39 m/s

3) As force is rate of change in momentum

Final momentum = 0.06 × (-35) , Initial momentum = 0.06 × 25

Change in momentum = 0.06 × 60 = 3.6 kg m/s

70 = 3.6 /∆t , ∆t = 3.6/70 = 0.051 sec