Physics

Here's the basic relationship:
Centripetal acceleration $a_c = v^2/r$, where $v$ is the speed and $r$ is the radius of the circle.
Centripetal force $F_c = ma_c = mv^2/r$, where $m$ is the mass.

It's important not to confuse centripetal force with a "centrifugal force." Centrifugal force is an apparent outward force you feel due to inertia when you're in a rotating frame of reference, but it's not a real force in the way centripetal force is. The true force is always directed inward.

Electricity deals with electric charges. There are two types: positive and negative. Like charges repel, and unlike charges attract. This force is called the electric force. When charges move, we call it current.

Magnetism is a force that acts on moving charges. It's also linked to magnetic fields, which are areas around magnets (or moving charges) where magnetic forces can be felt. You can't have magnetism without some form of moving charge, even if it's just electrons spinning in an atom to make a permanent magnet.

You'll explore how objects move and interact. We'll break this down into "how" (kinematics) and "why" (dynamics).

Kinematics is all about describing motion without considering the forces causing it. You'll typically deal with these quantities:

You'll mostly encounter two main types of waves:
* Transverse Waves: The disturbance moves perpendicular to the direction the wave travels. Imagine shaking a rope – the rope moves up and down, but the wave travels along the rope. Light waves are transverse.
* Longitudinal Waves: The disturbance moves parallel to the direction the wave travels. Think of a Slinky being pushed and pulled – the coils compress and expand in the same direction the wave travels. Sound waves are longitudinal.

These topics explore how energy behaves at fundamental levels and how it affects macroscopic systems.

Modern Physics largely breaks into two big areas: Quantum Mechanics and Special Relativity.