An ideal spring is in equilibrium, hanging from a ceiling with a
1 kg mass at the end. At rest, the length of the hanging spring is
10 cm. Then, an additional 5 kg block is added to the spring,
causing its length at rest to increase to 13 cm. The 5 kg block is
then removed. Starting from rest, when the 5 kg block is removed,
the spring begins to oscillate.
What will the spring’s velocity be, the third...