Question

Someone fires a 0.04 kg bullet at a block of wood that has a mass of 0.5 kg. (The block of wood is sitting on a frictionless surface, so it moves freely when the bullet hits it). The wood block is initially at rest. The bullet is traveling 300 m/s when it hits the wood block and sticks inside it. Now the bullet and the wood block move together as one object. How fast are they traveling?

Answer 1

Answer:

The speed of bullet and wooden bock coupled together, V = 22.22 m/s

Explanation:

Given that,

Mass of the bullet, m = 0.04 Kg

Mass of the wooden block, M = 0.5 Kg

The initial velocity of the bullet, u = 300 m/s

The initial velocity of the wooden block, U = 0 m/s

The final velocity of the bullet and wooden bock coupled together, V = 0 m/s

According to the conservation of linear momentum, the total momentum of the body after impact is equal to the total momentum before impact.

Therefore,

                              mV + MV = mu + MU

                               V(m+M) = mu

                                 V = mu/(m+M)

Substituting the values in the above equation,

                                V = 0.04 Kg x 300 m/s  / (0.04 Kg+ 0.5 Kg)

                                    = 22.22 m/s

Hence, the speed of bullet and wooden bock coupled together, V = 22.22 m/s