Q1. A rifle with the barrel length of 62cm fires a 12g bullet with a horizontal speed of 380m/s. The bullet strikes a block of wood and penetrates to a depth of 14cm. What resistive force (assumed to be constant) does the wood exert on the bullet? How long does it take bullet to come to rest after entering the wood?
Q2. A thundercloud has an electric charge of 43.6 C near the top of cloud and -38.7 C near the bottom of the cloud. The magnitude of electric force between these two charges is 3.95 x 10^6 N. What is the average separation between the charges?