MCAT Physical

A comprehensive introduction to the fundamental concepts of physics as tested on the MCAT, including mechanics, thermodynamics, electricity, and more.

Basic Concepts

Work, Energy, and Power

The Physics of Doing Things

Work, energy, and power are all about how things change and how much oomph is required to make them change.

Work

When a force moves an object over a distance, work is done. If you lift a backpack, you’re doing work against gravity.

  • Work formula: \( W = Fd\cos{\theta} \)

Energy

Energy is the ability to do work. There are different types:

  • Kinetic energy: Energy of motion (\( KE = \frac{1}{2}mv^2 \))
  • Potential energy: Stored energy, like a stretched spring or a raised object (\( PE = mgh \))

Power

Power is how quickly work is done.

  • Power formula: \( P = \frac{W}{t} \)

Everyday Applications

Understanding work and energy helps you figure out how much food you need for a workout, or why hybrid cars save fuel.

Examples

  • Calculating the energy a cyclist uses to pedal uphill.

  • Figuring out the power output of a hair dryer.

In a Nutshell

Work is using a force over distance, energy is the capacity to do work, and power is the rate at which work is done.