A 15g bullet is fired horizontally into a 3kg block of wood suspended by a long cord. Assume that the bullet remains in the block and that it swings 0.086m above the initial height. Calculate the velocity of the bullet when it strikes the wood.

261.3 m/s

Explanation:

Mass of bullet=m=15 g=

1 kg=1000g

Mass of block=M=3 kg

d=0.086 m

Total mass =M+m=3+0.015=3.015 kg

K.E at the time strike=Gravitational potential energy at the end of swing

Using g=

Substitute the values

Velocity after collision=V=1.3 m/s

Velocity of block=v'=0

Using conservation law of momentum

Using the formula

small = small current large mag large current