Force Cheat Sheet

Key Definitions

• Force (F): An interaction that causes an object to change its velocity. ✅

• Net Force: The vector sum of all forces acting on an object. ✅

• Friction: The force that opposes the relative motion of two surfaces in contact. ✅

Important Concepts

Newton's Laws of Motion

• First Law: An object remains at rest or in uniform motion unless acted upon by an external force. ✅

• Second Law: The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. ✅

• Third Law: For every action, there is an equal and opposite reaction. ✅

Types of Forces

• Contact Forces: Forces that act through direct contact (e.g., friction, tension). ✅

• Non-contact Forces: Forces that act at a distance (e.g., gravitational, electromagnetic). ✅

Key Formulas

• F: Net force (N)

• m: Mass (kg)

• a: Acceleration (m/s²)

f_friction = μN

• f_friction: Frictional force (N)

• μ: Coefficient of friction (dimensionless)

• N: Normal force (N)

Common Mistakes to Avoid

Common Mistake: Confusing mass with weight; mass is a measure of matter, while weight is the force due to gravity.

Memory Tricks

Tip: "F = ma" — Force = mass × acceleration.

Key Diagrams

   ↑
   |  F_net
   |
   |  -----> F_applied
   |  
   |  -----> F_friction
   |
   |  -----> F_gravity
   |
   |____________________>