Problem # p002

Work-Energy Method
A spring-driven pistol is loaded by compressing a spring ( spring constant k=2000 N/m ) by 30 cm from its relaxed position. A bullet (m=0.2 kg) is fired horizontally from a height (h=1.2 m) above the ground.


  1. To give you a feeling of how stiff that spring is, calculate by how much the spring would get compressed if YOU were to sit on it.

  2. With what velocity will the bullet leave the pistol if the mass of the spring and friction can be neglected and the spring has expanded to its relaxed state at the moment the bullet leaves the pistol ?

  3. What is the magnitude of the velocity with which the bullet hits the ground ? Neglect air resistance. g=9.81 m/s2