Question

Prob3: In a system of ballistic pendulum, a bullet of mass 5.0 g makes a completely inelastic collision with a block of mass of wood of mass 2.0 kg which is suspended like a pendulum. After the impact, the block swings up to maximum height of 3.0 m. What is the initial speed of the bullet?

Please help me with this. thank you

Answer 1

In this question we are going to use the concept of law of conservation of energy. When a bullet initially comes, all of its energy is the kinetic energy and when it strikes with the pendulum mass all of its energy get converted to the potential energy of the bullet-mass system. we are given the following information mb = 5g = 0.005kg mw = 2kg h = 3m g = 9.8 The kinetic energy of the bullet will be given by T; = mou? = }(0.005) v2 @ after the impact the potential energy of the bullet-mass system will be Vj = (mb + mw)gh = (0.005 + 2)(9.8)(3) @ now by the law of conservation of energy we can write T; =Vf @ (0.005)v2 = (0.005 + 2)(9.8)(3) E D solving for v we will get v= 153.554m/s