Physics (Forces, Tracks & Trains!)
Pressure is the amount of force pushing on a certain area. The size of pressure depends on the sidze of the force, and the size of the ara its pushing on. if there is high pressure under the wheel of a vehicle, it is more likely to sink into mud, sand or snow.
If you keep the size of the force the same:
- for a large area, the pressure will be low
- for a smaill area, the pressure will be high
If you keep the area the same:
- for a large force, the pressure will be high
- for a small area, th pressure will be low
A single train can transport thousands of tonnes of freight. there is a large force on the ground beneath the train. the tracks spread out the weight of the train so the wagons do not sink.
Presssure affects everyday things as well. It is easier to cut something with a sharp knife than with a blunt one. The sharp knife has a smaller edge, so the force you put on the knife is more concentrated.