Freefall (Cambridge International IGCSE Science)

Acceleration of free fall

Extended Tier Only

• In the absence of air resistance, all objects fall with the same acceleration regardless of their mass

• This is called the acceleration of freefall

  • This is also sometimes called acceleration due to gravity

$\mathrm{acceleration} \mathrm{of} \mathrm{freefall}=g=9.8m/s^{2}$

In the absence of air resistance, Galileo discovered that all objects (near Earth's surface) fall with an acceleration of about 9.8 m/s²

• This means that for every second an object falls, its velocity will increase by 9.8 m/s

Exam Hint

• The symbol $g$ also stands for the gravitational field strength, and can be used to calculate the force of weight acting an object using its mass:

$W=mg$

• Where:

  • $W$ = the force of weight acting on an object, measured in newtons (N)
  • $m$ = mass of object, measured in kilograms (kg)
  • $g$ = gravitational field strength, measured in newtons per kilogram (N/kg)