A Bullet weighing 4.5 × 10-³kg is fired horizontally into a 1.8kg wooden block at rest on a horizontal surface. The coefficient of the kinetic friction between block and surface is 0.20 the bullet comes to rest in the block which moves 1.8m, find the speed of the bullet​

Abumper car with a mass of 250 kg is traveling at a speed of 4 m/s. this bumper car collides and sticks to a second bumper car with a mass of 250 kg, which is initially at rest. what is the final speed of these two bumper cars after the collision, assuming they remain stuck together?