What are fluids?
We know that there are 3 forms of Matter
- Solids (Example - Ice)
- Liquids (Example - Water)
- Gases (Example-Water Vapour)
Fluid is the common name given to liquid and gases
Is force of friction only exerted by solids?
No
It is exerted by all forms of matter-solids or fluids(liquid and gases)
What is fluid friction
Frictional force exerted by liquids and gases is called fluid friction
It is also called Drag or Drag Force
Example 1
When an aeroplane flies in air,it faces resistance from air which reduces its speed
This air resistance is frictional force of air or fluid friction
Example 2
When a speedboat moves in sea,it faces resistance from water in the sea which reduces its speed
This is frictional force of water or fluid friction
Factors which Effect Fluid Friction
Speed of Object
More the speed of object,more will be fluid friction.Less the speed ,less the fluid friction
Example A speed boat will face more friction compared to a paddle boat
Shape of Object
If object is streamline(pointed from front),they face less fluid friction
But if object is not streamlined,it faces more friction
Example - A truck will face more friction compared to a car
Size of Object
larger the size of object,more the friction
Smaller the size,less the friction
Example - A ship will face more friction compared to a boat
Nature of fluid
If fluid is more viscous or thick,there will be more friction
If fluid is less viscous or thin,there will be less fiction
Example - Water is thicker than air,so there is more friction in water compared to air.This is why aeroplanes move faster than ships
Why it is important to reduce fluid friction?
It is important to reduce fluid friction because
Reduces Speed
Fluid friction reduces speed of vehicle.(If there was no friction,vehicle would move faster)
Increase Costs
it reduces efficiency and increase cost of running vehicle(More fuel is required to overcome fluid resistance)
How to Reduce Fluid Friction?
Fluid friction is reduced by streamlining shape of vehicle
This is done by making it pointed from front like a bird
Also wings are provided in case of aeroplane
This help in reducing air resistance and increasing speed and efficiency of object
Example 1
Front of Aeroplanes are pointed .They also have wings,This reduces friction in air and make aeroplane travel faster
Example 2
Boats and Ships are also pointed in front.This reduce friction in water
Example 3
Similarly, car is also streamlined to reduce air resistance (or drag)
