AP Physics C Mechanics · Question of the Day

AP Physics C Mechanics Question of the Day

A fresh daily question to build accuracy, reinforce recall, and turn practice into a steady habit.

Thursday, October 8, 2026

An object of mass $m$ is attached to an ideal horizontal spring with spring constant $k$ . The object is displaced from its equilibrium position by a distance $A$ and released from rest. Assuming no friction, what is the total mechanical energy of the object-spring system?

Keep practicing AP Physics C Mechanics

Question of the Day

Answer today's AP Physics C Mechanics question, reveal the full explanation, then keep the streak going with a new question every day.

$E = \frac{1}{2}mv^2$
$E = \frac{1}{2}kA^2$ (correct answer)
$E = \frac{1}{2}kA$
$E = \frac{1}{2}mA^2$

Explanation: The total mechanical energy of a simple harmonic oscillator is constant. At the point of maximum displacement (the amplitude $A$ ), the object is momentarily at rest, so its kinetic energy is zero. At this point, all the energy is stored as potential energy in the spring, which is given by $U_s = \frac{1}{2}kA^2$ . Therefore, the total mechanical energy is $E = \frac{1}{2}kA^2$ .