These questions on my hw are so hard. anyone get them? "The Spring constant for the spring in a special cannon is 1800N/m. In cocking the cannon, the spring is compressed .55m. What is the initial speed of a 7.0 kg cannonball at rest on the free end of the spring when it is released?" "I went bugee jumping and I was standing on a platform that is 46.0m high. My mass is 68.0kg and my bungee cord is 9.00 m long (unstretched). The cord behaves like an ideal spring and has a constant of k=66.0N/m. I fall off the platform from rest and I want you to tell me my velocity when I am (a) 37 m off the ground and (b) 15 m off the ground."