Question

A rifle bullet with mass 15.0 g strikes and embeds itself in a block of mass 1.500 kg that rests on a frictionless, horizontal surface and is attached to a coil spring. The spring was relaxed at the beginning. The spring constant is 550 N/m. The initial velocity of the bullet was 700 m/s. The impact compresses the spring by x (see figure below). 1) Find the magnitude of the block's velocity (with the bullet stuck inside) after the impact (collision), just before it starts compressing the spring 2) Find the distance x, that the spring will be fully compressed after the impact. 3) Calculate the initial total mechanical energy of the system, bullet and block (before collision, as in the picture above, block at rest, spring is relaxed). 4) Calculate the final total mechanical energy of the bullet and block, after the collision and just before they started compressing the spring (spring is still relaxed). 5) Calculate the final total mechanical energy of the system at the moment when the block (with bullet inside) was stopped by the compressed spring. 6) Was any of kinetic energy lost during the collision? How much? 7) Was the collision elastic or inelastic? Why?

Answer 1