I attach a 2.0-kg block to a spring that obeys Hooke's Law and supply 16 J of energy to stretch the spring.I release the block;it oscillates with period 0.30 s.The amplitude is:
A)38 cm.
B)19 cm.
C)9.5 cm.
D)4.3 cm.

Question

Quizplus · Accepted Answer

The energy supplied to the spring is equal to the potential energy at maximum amplitude: $ E = \frac{1}{2} k A^2 $. Given $ E = 16 $ J, solve for $ A $ using the period $ T = 0.30 $ s to find $ k $ from $ T = 2\pi \sqrt{\frac{m}{k}} $.

I Attach a 2