§9.3 — Conservation of Momentum

Conservation of momentum is one of the most fundamental laws in physics and follows directly from Newton’s second law for the center of mass (§9.2).…

§9.4 — Impulse and Collisions

Impulse is a concept that represents a large force acting over a short time. It is very useful for analyzing collisions and explosions. This section…

§9.5 — Angular Momentum

Until now we have studied linear motion of objects. But many objects rotate. Car wheels, soccer balls, planets, and even electrons have rotational…

§9.6 — Rigid Body Dynamics

Now we know that: – Center of mass represents translational motion (§9.1–9.3) – Angular momentum represents rotational motion (§9.5)

§10.1 — Rotational Kinematics

So far we’ve studied linear motion — an object moving along a line or in a plane. But many objects rotate: wheels, electrons in atoms, planets, even…

§10.2 — Moment of Inertia

A simple question: which is harder to spin? (1) A houseplant or (2) a steel wheel of the same mass? Obviously the wheel. But why? Both have the same…

§10.4 — Rotational Kinetic Energy

A spinning football thrown through the air has two types of kinetic energy: 1. Translational kinetic energy: from the motion of its center of mass 2.…

§10.5 — Rolling Motion

Billiard balls on a table, bicycles on a street, car wheels — they all roll. Rolling is a perfect blend: – Linear motion: center of mass moves…