A drawing pin barely needs a push to pierce a board, yet the same finger pressing flat does nothing. The force has not changed, only the area it acts on. Concentrate a force onto a tiny area and the pressure soars; spread it wide and it gently shares the load.
Pressure is the force acting per unit area: p = F ÷ A, measured in pascals (Pa), where one pascal is one newton per square metre. For the same force, a smaller area gives a larger pressure.
Pressure is the force acting per unit area, at right angles to the surface.
One pascal is one newton per square metre. For a fixed force, a smaller area means a larger pressure.
Keep the force fixed and change the area it acts on. The pressure reading climbs sharply as the area shrinks, which is exactly why blades and points are made thin.
Four quick checks on the equation, its unit, and the area effect. Each correct answer earns XP and lights this skill on your star map.
Pressure is calculated as...
Pressure is measured in...
One pascal is equal to...
For the same force, a smaller area gives a...
The defining equation and its rearrangement for force:
A box weighing 150 N rests on the floor, in contact over an area of 0.30 m². Find the pressure it exerts on the floor.
Two slips cost marks here. First, divide the force by the area, do not multiply. Second, when an object simply rests on a surface, the force is its weight, so a mass in kilograms must be turned into a weight in newtons with W = mg before you divide.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
A force of 200 N acts at right angles on an area of 0.50 m². The pressure is...
Snowshoes stop a walker sinking into soft snow because they...
A 60 kg person stands on one foot of area 0.015 m². Taking g = 10 N/kg, the pressure on the floor is...
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