If the stone is thrown up vertically and return to the ground, its potential energy is maximum
a) During the upward journey
b) At the maximum height
c) During the return journey
d) At the bottom

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.