Rotational Motion
Rotational Motion is one of the most important mechanics chapters in JEE Main Physics.
It explains angular motion, torque, moment of inertia, rolling motion, angular momentum,
and rotational dynamics. This chapter is concept-heavy and frequently tested in JEE Main.
Topics Covered
- Angular Displacement, Velocity and Acceleration
- Relation Between Linear and Angular Quantities
- Torque
- Moment of Inertia
- Radius of Gyration
- Theorems of Moment of Inertia
- Angular Momentum
- Conservation of Angular Momentum
- Rotational Kinetic Energy
- Rolling Motion
- Center of Mass in Rotation
- Equilibrium of Rigid Bodies
Important Formulas
Torque:
τ = r × F
Angular Momentum:
L = Iω
Rotational Kinetic Energy:
K = ½Iω²
Angular Equation:
ω² = ω₀² + 2αθ
Rolling Motion:
v = rω
Radius of Gyration:
I = Mk²
JEE Main Preparation Tips
- Memorize standard moment of inertia values.
- Practice torque and angular momentum problems regularly.
- Master rolling motion concepts.
- Focus on theorem-based moment of inertia questions.
- Solve previous year JEE Main questions for speed and confidence.
