A block of mass is attached to a horizontal ideal spring of force constant on a…
PHYSICS · Multi-part · GCSE · Physics · Energy · Energy
Problem
A block of mass m is attached to a horizontal ideal spring of force constant k on a frictionless surface. The spring is compressed a distance x0 from its relaxed (natural) length and then released from rest.
(1) Taking the relaxed length of the spring as the position where elastic potential energy is zero, determine the block’s speed as it passes through the relaxed length.
(2) Suppose instead the reference position for elastic potential energy is chosen at the point of maximum compression. Recalculate the block’s speed as it passes through the relaxed length using this new reference choice.
(3) Compare your answers to parts (a) and (b). Explain why the change in reference position has no effect on the predicted speed, even though individual values of potential and total mechanical energy are different.