A ballistic pendulum is a device often used for measuring the velocity of a projectile. Assume to projectile fully embeds itself in the pendulum. If the projectile mass is 25 grams, the pendulum mass is 2.5 kg, and the vertical displacement of the pendulum after the collision is 12 cm, find the velocity of the projectile just prior to the collision.

Explanation:

pendulum rises upto height of .12 m

velocity of projectile and pendulum after collision = √ ( 2gH )

= √ ( 2 x 9.8 x .12 )

= 1.53 m / s

Applying conservation of momentum during collision

mv = (m + M ) X V

m and M are mass of projectile and pendulum and v and V are velocity of projectile before and after collision .

.025 x v = ( 2.5 + .025 ) x 1.53

v = 154.5 m /s