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Physics · Class 11

Roll a ring, cylinder or sphere

Particles & Rotational Motion

Gravitational energy becomes both translational and rotational kinetic energy. Bodies with a smaller shape factor need less rotational energy per unit speed and accelerate faster. The no-slip condition is v=ωr.

Open the interactive experiment →

Roll a ring, cylinder or sphere

சறுக்காமல் உருளும்போது v = ωr. நிலைமத் திருப்புத்திறன் குறைவான வடிவம் சரிவில் வேகமாக முடுக்கம் பெறும்.

Key notes, relationships and model limits

Key relationship

a = gsinθ/(1+β); v=at; ω=v/r; β=I/(Mr²).

Remember

Gravitational energy becomes both translational and rotational kinetic energy. Bodies with a smaller shape factor need less rotational energy per unit speed and accelerate faster. The no-slip condition is v=ωr.

Common trap

Static friction in ideal rolling does no work at the stationary contact point.

Model limits

Rigid bodies start from rest and roll without slipping down an ideal slope. Static friction is sufficient; no rolling resistance. The horizontal axis is simulation time.

What you will learn

Link rolling kinematics, shape-dependent inertia and energy partition.

Try the experiment

Try both scenarios, change one control, and predict the result before checking the graph and readouts.

Think of it this way

Change one input while keeping the others fixed, as you would in a controlled experiment.

Worked example

At 20°, sphere a=9.81sin20°/1.4=2.40 m/s², cylinder a=2.24 m/s² and ring a=1.68 m/s².

Why this matters

The model connects roll a ring, cylinder or sphere with an observable reading. Check the equation and assumptions before applying it.

Before you start

SI units · algebra · graph reading

Check your understanding

Which reaches a given distance first on this ideal slope?

Read the explanation

The shape factors are sphere 0.4, cylinder 0.5, ring 1; acceleration decreases as β increases.

Course connection: Class XI Chapter 6. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.