Laws of Motion
Class 11 · Laws of Motion

Atwood's Pulley

Two masses over a pulley — live acceleration and tension from a = (m₂−m₁)g/(m₁+m₂).

Key Notes

01

Two masses m₁ and m₂ over a massless, frictionless pulley.

02

a = (m₂ − m₁)g / (m₁ + m₂), with heavier mass falling.

03

Tension T = 2m₁m₂g / (m₁ + m₂).

04

For equal masses, a = 0 and T = mg.

Formulas

Atwood acceleration

Shared magnitude of acceleration.

Atwood tension

Same throughout ideal string.

Important Points

T is always between m₁g and m₂g (harmonic mean).

Atwood's Pulley 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.