// physics › Density & Pressure
Find pressure from force and area, or solve for force or area, using P = F / A.
P = F / A
Pressure is how concentrated a push is — how much force is squeezed onto each bit of area. Press your finger gently on a table: low pressure. Press the same finger on a sharp pin with the same force: huge pressure on that tiny point, which is why it hurts.
Because a sharp edge is very thin, so it puts your pushing force onto a tiny area. Small area with the same force means very high pressure, enough to cut. A blunt knife spreads the force over a wider edge, so the pressure is too low to slice.
Yes. Push with a force of 20 N onto an area of 0.5 square metres. Pressure = force ÷ area = 20 ÷ 0.5 = 40. So the pressure is 40 pascals (Pa). A pascal just means one newton pushing on one square metre.
Rearrange the same formula. Force = pressure × area, and area = force ÷ pressure. Choose what you want in the 'Solve for' box and it works it out for you.
Snowshoes spread your weight over a big area so the pressure is low and you do not sink into snow. Camels have wide feet for the same reason in sand. High heels do the opposite — all the weight on a tiny tip makes a big dent.