Definition of Pressure
Pressure is the force applied per unit area.
SI Unit: Pascal (Pa)
1 Pascal = 1 Newton per square meter (N/m²)
Formula:
Pressure= Force/Area
Pressure in Daily Life
1. Why do knives have sharp edges?
A knife has a very sharp and thin edge, which means the area of contact is very small.
When the same amount of force is applied on a smaller area, the pressure becomes very high.
This high pressure allows the knife to cut fruits, vegetables, or other materials easily.
So, a sharp knife works better because it produces more pressure with the same force.
2. Why do camels have broad feet?
Camels live in deserts where the sand is soft and loose.
If an animal has narrow feet, its weight is concentrated on a small area, causing it to sink into the sand.
But camels have broad and wide feet, which increases the surface area.
As a result, the pressure on the sand becomes less, and the camel can walk comfortably without sinking.
3. Why do nails have pointed tips?
A nail has a sharp, pointed tip that touches the surface with a very small area.
When a hammer is used, the force applied on the nail is concentrated on this tiny area.
This produces very high pressure, allowing the nail to enter wood or walls easily.
Once the pointed tip enters, the rest of the nail follows with less effort.
4. Why do school bags have broad straps?
If a bag has thin straps, the weight of the bag is concentrated on a small area of the shoulders, causing high pressure.
This high pressure can be painful and may even hurt the skin.
Broad straps increase the surface area, spreading the weight over a larger region.
This reduces the pressure on the shoulders, making the bag more comfortable to carry.