Halliday, Resnick & Walker — Potential Energy and Conservation of Energy: Problem 28

28 Figure 8-29a applies to the spring in a cork gun (Fig. 8-29b); it shows the spring force as a function of the stretch or compression of the spring. The spring is compressed by 5.5 cm and used to propel a 4.2 g cork from the gun. (a) What is the speed of the cork if it is released as the spring passes through its relaxed position? (b) Suppose, instead, that the cork sticks to the spring and stretches it 1.5 cm before separation occurs. What now is the speed of the cork at the time of release?