Centripetal vs Centrifugal Force Explained Clearly

at first glance centripetal force looks strange consider this situation the moon

revolves around the earth the moon has a velocity as shown at a particular instant

however to make this circular motion the force should be perpendicular to the velocity

as shown in mechanics we generally see velocity in the direction of the applied force

why then is centripetal force perpendicular to the velocity what is centrifugal force let's figure

it out with an interesting thought experiment consider this tennis ball

and assume it's moving on a straight line initially if you apply force perpendicular to its

motion for a short time the object will deflect as shown its direction changes

now let's apply the force again perpendicular to the new direction the object deflects again let's repeat

this process now observe the shape the object traveled

it's very close to a circle if the time interval of applied force is significantly smaller

you will get a more perfect circle which means if an object is always acted upon with a force

perpendicular to its velocity the object will move in a circle this force is known as centripetal force

one more logical conclusion would be that more the centripetal force more will the object's deflection or

lesser will be the radius of the circle this means for any circular motion to occur inward perpendicular force

must act upon the object to get the value of the centripetal force we should approach the problem

analytically and start with the way sir isaac newton defined force

however there's no fun in an analytical derivation so we'll animate this method the

conceptual understanding we already developed will really help you in science

and engineering once again it is clear from this equation that the lesser the radius of

the circle the more centripetal force will be needed

when the moon revolves around the earth the gravitational force acting between the moon and the earth

provides the necessary centripetal force similarly when you rotate an object attached to a string

the tension in the string provides the required centripetal force consider this spinning wooden block the

frictional force between the block and floor lends the necessary centripetal force

in short centripetal force should be supplied by some external source such as gravitation

tension friction etc now that we've learned the concept of centripetal force the big question is

what is centrifugal force consider these examples when fluid spins in a beaker as the

speed of the beaker increases the fluid flows outward similarly in this centrifugal casting

process the molten metal always moves to the outer wall

as you increase the speed of this suspended ball the ball also travels outward

is there any force called the centrifugal force which is acting radially outward on a rotating object to

move it outward scientifically speaking there is no such force as a centrifugal force

it's a pseudo force a rotating object always needs a force which is radially inward

centrifugal force is needed in physics only when you analyze the problem rotating along with the object

in this example since the observer is sitting inside a rotating cabin the observer has to add a centrifugal

force to analyze the problem it's a pseudo force added to convert a non-inertial frame of reference

to an inertial frame of reference if the observer is on the ground there is no need to use such a force

now let's analyze the previous examples using the concept of centripetal force we have developed

as you rotate the ball faster it moves away the ball needs a centripetal force the

tension of the rope more specifically the horizontal component of its tension provides that force the tension on the

ball has one more responsibility the vertical component of the tension

has to balance the weight of the ball logically as the ball rotates faster the rope's tension

should increase to supply the sufficient centripetal force however the weight of the ball does not

increase which means that in order to keep the vertical component of the tension the same

the angle has to increase like this this is the reason why the ball moves away as you rotate it faster

the case of the rotating fluid is slightly different here again each fluid particle requires

a particular amount of centripetal force to maintain the circular motion the pressure difference caused by the

water level's height disparity generates that centripetal force the fluid

particles at the outer radius obviously need more centripetal force to satisfy this increasing centripetal

force requirement the fluid surface has to form a curved shape

rather than a straight line when the water volume rotates faster each particle demands

more centripetal force or more pressure difference across the particle

therefore the water surface curves more than in the previous case or you feel like the water is going

outward it's better to avoid using centrifugal force in your scientific or

engineering analyses because it's a pseudo force used only in some special cases always

work using centripetal force that's the real force that a rotating object requires