In class i mentioned that we used to show an actual ballistic pendulum where a rifle is shot into a heavy block to see how the block moves. assume a 4.7 gram bullet is fired at 678 m/s into a 4.8 kg block of wood. the block hangs from a long string to approximate 1d motion. how fast does the block move just after the collision in m/s?

Suppose a force of 60 n is required to stretch and hold a spring 0.1 m from its equilibrium position. a. assuming the spring obeys hooke's law, find the spring constant k. b. how much work is required to compress the spring 0.5 m from its equilibrium position? c. how much work is required to stretch the spring 0.6 m from its equilibrium position? d. how much additional work is required to stretch the spring 0.1 m if it has already been stretched 0.1 m from its equilibrium? a. kequals 600