Centripetal, centrifugal force; differences, comparison and examples

Are you a little bit confused about the differences between centripetal and centrifugal force?  Well then, carry on.

Centripetal Force

Definition:

It is defined as that inward force required to keep objects moving with a constant speed in a circular path.

Formula:

F = mv2/r
V = rw
= Mrw
Where, "F" is the centripetal force, "m" is the mass of body, "v" is the velocity at
which the body is moving, "r" is the radius and "w" is angular velocity.

Direction:

The direction of a centripetal force of a body Is perpendicular to the direction of the velocity.

Type of force:

Centripetal Force keeps an object moving in its circular path, and prevents it from flying off.

Example:

When you tie a string to a stone, which is then whirled in a Circular path is suddenly cut, the stone files off the circular path.
Centripetal Force was the force keeping the stone in its initial circular path.

Centrifugal force

Definition:

It is defined as that outward force required to keep it moving in circular path.

Condition:
It must be according to Newton’s third law of motion.

Formula:

F = mv2/r

Direction:

The direction of a centrifugal force of a body is equal and oppositely directed away from the center from which the body is moving.

Type of force:

centrifugal force is the inertia of motion.

Example:

Driving on a mud road and children feeling a force pushing them outwards.

Angular velocity (w)

This is defined as the angle turned through divided by the elapsed time. Consider a stone whirled in a circular path. It move from the point A to B in T Seconds, so that the radius OA sweeps through the angle ɵ.

Angular velocity (w) = ɵ/t

Linear velocity (v) = s/t

Linear displacement (s) =

Where s is the length of arc AB, which is equal to linear displacement. If the angle ɵ is measured in radians.
The unit of radius is metre.
The unit of angular velocity is radians per second.
The unit of linear velocity is metre per second.
360° = 2π = One revolution
180° = π

Example
A stone whirled at the end of a road 30cm round, makes ten revolution in two seconds. Find:
a)     The angular velocity in radians per second.
b)     The  linear speed,
c)     The distance covered in 5 seconds.

Solution,

W = ɵ/t

w = 20/2 = 10π rad/s

w = (10 x 3.14) rad/s

According to Ganse, “Centripetal force and centrifugal force are really the exact same force, just in opposite directions because they're experienced from different frames of reference.”

Previous Post
Next Post

Unknown

1. 2. 