To calculate the average pressure exerted by a force acting perpendicularly on a flat surface, the size of the force must be known. What else needs to be known?
The area of the surface over which the force acts is needed (✓\checkmark✓) and the duration of time for which the force acts is needed (✓\checkmark✓)
The area of the surface over which the force acts is needed (✓\checkmark✓) and the duration of time for which the force acts is not needed (×\times×)
The area of the surface over which the force acts is not needed (×\times×) and the duration of time for which the force acts is needed (✓\checkmark✓)
The area of the surface over which the force acts is not needed (×\times×) and the duration of time for which the force acts is not needed (×\times×)
188 exam-style questions on CIE IGCSE Physics Pressure, covering Pressure. Each one has a worked solution and a mark scheme showing where the marks go.