Mechanics · Physics

Masses & Springs Simulation

Hang masses on springs and let them bounce. Change k, damping and gravity, compare two springs side by side, and time the period T = 2π√(m/k).

Interactive virtual lab · no download · works on phones and laptops

Chapter: Oscillations
For: Class 11 · JEE · NEET
Time: ~15 min

Masses & Springs is a Pro simulation

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How to use it

1Drag a mass onto a spring hook.
2Pull the mass down and let go.
3Change spring constant, damping and planet.
4Use the stopwatch and the energy bars.

What to notice

The period depends on m and k, not on the amplitude or on g.
At equilibrium the spring stretches mg/k.
Velocity is largest at equilibrium; acceleration is largest at the ends.
Damping turns the oscillation's energy into heat.

For teachers

A ready-made teaching kit comes with this lab

Lesson plan
22 min, 4 steps
Ask the class
3 questions with answers
Quick quiz
6 questions, printable
Key formulas
4 formulas

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About the Masses & Springs simulation

Hang a mass on a spring and pull it down: it bobs up and down in simple harmonic motion. The stiffer the spring or the lighter the mass, the faster it oscillates. Unlike a pendulum, the period of a spring does not depend on g — gravity only shifts where the mass sits at rest.

In this mass–spring simulation you hang different masses, change the spring constant, add damping and watch the kinetic, gravitational and elastic energy bars trade places as it oscillates. Measure how far the spring stretches to find k, then time the oscillations to check T = 2π√(m/k). It is built for the Oscillations chapter of Class 11 and for JEE and NEET problems on springs.

Also covers: simple harmonic motion, shm, spring mass system, time period, damping, planet x.

Frequently asked questions

Does gravity change the period of a mass on a spring?

No. Gravity moves the equilibrium position down by mg/k, but the oscillation about that point still has T = 2π√(m/k). The same spring would oscillate at the same rate on the Moon.