Question

A bullet of travelling of mass 10 g travelling horizaontally with a velocity of 150 m /s strikes a stationary wooden block and comes to rest in 0.03 seconds . calculate the distance of penetration of the bullet . also calculate the force exerted on the bullet by the block

Answer 1

Data:
mass of the bullet (m) = 10 g = (10/1000) kg =0.01 kg
Initial velocity (u) = 150 m/s
Final velocity (v) = 0 m/s
Time taken (t) = 0.03 sec

i. Calculation of the distance of penetrationof the bullet into the block:  

Calculation of the distance of penetrationof the bullet into the block = Displacement

Displacement = average velocity × time
Displacement = [(u + v) / 2] × time
Displacement = [(150 + 0) / 2] × 0.03
Displacement = 2.25 m


ii. Calculation of the magnitude of the force exerted by the wooden block on the bullet:
the magnitude of the force exerted by the wooden block on the bullet = Retarding force
Retarding force = mass × reatardation
Retarding force = mass ×[ (Intitial velocity - Final velocity) / t ]
Retarding force = 0.01 ×[ (150 - 0) / 0.03 ] N
Retarding force = [150/3] N
Retarding force = 50 N

Answer 2

ur answer is attached.......