## Types of Forces

Questions on the Physical Sciences section of the MCAT assume Newton’s Three Laws of Motion. Application of these concepts, especially Newton’s Second Law of Motion, is an important skill to master. For any given MCAT problem, there can be 3 types of forces.

- Gravitational Forces
- Magnetic Forces
- Contact Forces

## Newton’s Three Laws of Motion

**Newton’s First Law of Motion.** Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

**Newton’s Second Law of Motion.**The acceleration of a body is directly proportional to, and in the same direction as, the net force acting on the body, and inversely proportional to its mass. Thus, **F = ma**, where F is the net force acting on the object, m is the mass of the object and a is the acceleration of the object.

**Newton’s Third Law of Motion.** When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction to that of the first body. For every action there is an equal and opposite reaction.

## Introduction to Forces

In physics, forces are analyzed and represented using vector diagrams. Every vector, and therefore force, has two properties – a direction and a magnitude. The fundamental skill for solving force problems in physics is understanding how to properly use vectors to find solutions. Another basic skill of problem-solving in physics is the ability to correctly use trigonometric functions.