Start learning →

The time period of a spring-mass system with mass $m$ and spring constant $k$ is:

A$T = 2\pi \sqrt{\dfrac{k}{m}}$
B$T = 2\pi \sqrt{\dfrac{m}{k}}$
C$T = 2\pi k m$
D$T = 2\pi (k + m)$
Answer & Solution
Correct answer: B. $T = 2\pi \sqrt{\dfrac{m}{k}}$
Spring-mass system: Newton's second law gives $m\ddot x = -kx$, hence $\omega = \sqrt{k/m}$. Period: $T = \dfrac{2\pi}{\omega} = 2\pi\sqrt{m/k}$. A stiffer spring (larger $k$) gives a shorter period. A heavier mass gives a longer period. Option A inverts the ratio, the classic trap.
Practise this question with Quill — AP Physics 1 →

Keep practising Unit 4B: Conservation of Linear Momentum & Collisions

Browse all Unit 4B: Conservation of Linear Momentum & Collisions questions for AP Physics 1, or explore more Physics topics.

Start a Unit 4B: Conservation of Linear Momentum & Collisions lesson →