Newton’s Second Law

• Newton's Second Law:

  • Newton's second law of motion states:The acceleration of an object is proportional to the resultant force acting on it and inversely proportional to the object's mass
• Newton's second law explains the following important principles:

  • An object will accelerate (change its velocity) in response to a resultant force
  • The bigger this resultant force, the larger the acceleration
  • For a given force, the greater the object's mass, the smaller the acceleration experienced
• • The image below shows some examples of Newton's second law in action:

  
• Objects like baseballs and lawnmowers accelerate when a resultant force is applied on them. The size of the acceleration is proportional to the size of the resultant force.
• Calculating Force & Acceleration:

  • Newton's second law can be expressed as an equation:

  F = ma
• • Where:
  • F = resultant force on the object in Newtons (N)
  • m = mass of the object in kilograms (kg)
  • a = acceleration of the object in metres per second squared (m/s2)
• • This equation can be rearranged with the help of a formula triangle: