Motion in a Plane
Class 11 · Motion in a Plane

Uniform Circular Motion

Ball on a circle at constant ω — live v (tangent) and a (toward center) arrows.

Key Notes

01

Speed is constant but velocity direction changes → centripetal acceleration.

02

a_c = v²/r = ω²r, directed toward the center.

03

Angular velocity ω = 2π/T = 2πf; linear velocity v = ωr.

04

Centripetal force F_c = mv²/r = mω²r (always needed, provided by string/gravity/friction/etc.)

Formulas

Centripetal acceleration

Always toward the center.

Period

Time for one revolution.

Important Points

Centripetal force is a requirement, not a new type of force — it's the name for the net radial force.

Uniform Circular Motion notes from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 11 physics revision for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG.