Class 11 · Laws of Motion

Force Resolution

Resolve a force at angle θ into Fx = F cosθ, Fy = F sinθ — see the components in real time.

Key Notes

01

A force F at angle θ has rectangular components Fx = F cosθ, Fy = F sinθ.

02

Components depend on the chosen axes — pick axes that simplify the problem (along motion / along incline).

03

Magnitude is recovered as F = √(Fx² + Fy²); direction as tanθ = Fy/Fx.

Formulas

Components

Rectangular resolution along axes.

Magnitude

Pythagoras.

Important Points

Cosθ goes with the axis the force is closer to.

On an incline of angle α, gravity resolves as mg sinα (down-incline) and mg cosα (normal).

Force Resolution 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.