A spring loaded gun launches a 10g ball into a 60g pendulum bob that is initially at rest. The ball gets stuck in the pendulum and together they swing to a height of 3.5 cm. If the spring was initially compressed 2.0 cm before launching the ball, what is the spring constant of the spring?.

Question

jfraser · Answer

you need to use conservation of energy and set the final potential energy of the (ball + bob) system equal to the initial kinetic energy of the ball, and then use that energy in the spring constant equation

irishboy123 · Answer

you need to use conservation of energy and set the final potential gravitational energy of the (ball + bob) system equal to the initial ***potential spring energy*** of the ball/spring mechanism.