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Real Life Applications
3 min read

Laws Of Motion

- Wondering why to study this chapter? Know the real world use of it
Friction in the real world

Friction as you know, is the resistance faced by an object when rubbing against another surface. Friction is present everywhere. No surface is completely smooth or in other words, frictionless. Without this force every little activity we do, be it holding a glass of water to walking on a floor would be next to impossible. Let's understand the role of friction in walking.
For a standing man, the force the man applies to the ground is his weight, say, which is balanced by the normal reaction of the ground.
If the man intends to walk forward, the man has to incline forwards such that the force applied on the ground( ) is at an angle, say to the ground.
On resolving it,
the Y-component, is balanced by the ground normal reaction, N.
the X-component, is balanced by the static friction from the ground,
If the friction on the ground did not exist, what would happen? The person would slip and fall every time he exerts an inclined force on the ground. Thus, its the friction that propels a person forward while walking.
Imagine, if you cannot even walk if friction did not exist, what else would be deemed impossible without friction?
What Would Happen if Friction Stopped Working?
5 mins
How does a centrifuge work?

Whenever you sit on a merry go round do you feel a force that is trying to throw you off outwards? This force is the centrifugal force, which is a pseudo force. For an observer standing away from the merry go round( inertial frame of reference) this force does not exist. But in the rotating reference frame(non-inertial reference frame) of the person sitting on the merry go round there exists a force opposing the centripetal force trying to throw the person outwards.
This inertial effect which a rotating particle feels in its own rotating frame is put to good use in centrifuges. When a sample is rotated in high speeds in a centrifuge, the sample particles experience a centrifugal force pulling  them towards the base. This force along with the inertia of the particles, carries the particles to the base of the centrifuge. Higher the inertia( mass) more close they will shift to the base of the test-tube in a centrifuge
This process has multiple applications in the real world, from your good old washing machine dryer to DNA extraction in samples in centrifuges. Check out this story to learn about centrifugation and its applications.
Centrifugation- A Method of Separation
2 mins
Can Centrifugal force be used to create Artificial Gravity?

Now you know, that every rotating object in its frame of reference experiences a fictitious force pulling it away from the centre of the circular path. Scientists claim this force can be used to stimulate gravity in space. The centripetal force experienced by a particle of mass moving with velocity in a path of radius is . The centrifugal force is exactly equal and opposite of it. To generate earth like gravity this force has to be equal to a person's weight on earth.

where is the angular velocity

Hence for a spaceship of radius R as shown below if rotated with angular velocity will generate a force equivalent to earth's gravity which will pull all the objects inside the spaceship towards the walls.
But is this practically possible? Check out this video to learn more.
Can We Create Artificial Gravity?
7 mins