What is centripetal force What is centrifugal force Applications of centrifugal force (Washing Machine Dryer, cream separator)

1. CENTRIPETAL FORCE
UNIT 3: DYNAMICS

2. What is centripetal force

3. EXAMPLES
 Spinning a ball tied with a string: Here the centripetal
force is provided by the force of tension on the rope pulls
the object in toward the centre.
 Turning a car: Here the centripetal force is provided by
the frictional force between the ground and the wheels.
 Planets orbiting around the Sun: Centripetal Force is
provided by Gravity.

5. What is the formula of centripetal force
According to Newton second law of motion a net force causes acceleration in
the body.
Hence centripetal force Fc causes centripetal acceleration in the body moving in
circle. Mathematically
Fc = mac
But, centripetal acceleration = ac =
𝑣2
𝑟
-- Fc =
𝑚𝑣2
𝑟
This formula shows that centripetal force needed by a body moving in circle
depends on mass of body, square of velocity, radius r of circle.

6. CENTRIFUGAL FORCE
 Centrifugal force is the reaction of
centripetal force.
 It is equal in magnitude and opposite
in direction of centripetal force.

7. APPLICATIONS OF CENTRIFUGAL FORCE
• BANKING OF THE ROADS
• WASHING MACHINE DRYER
• CREAM SEPERATOR

8. BANKING OF THE ROADS
• Banking of roads is the phenomenon in
which the edges are raised for the
curved roads above the inner edge.
• The friction between the tyres and the
road provides necessary centripetal
force.
• If friction is not enough, the car would
skid.
• Banking causes a component of weight
of vehicle to provide the necessary
centripetal force while taking a turn.

10. WASHING MACHINE DRYER
• The dryer of washing machine is basket
spinner, having a perforated wall with many
fine holes.
• The centripetal force between clothes and
inside of drum pushes them around in circle.
• As a reaction, centrifugal force makes water
fly out and get clothes dry.
• Clothes experience centripetal force but
water does not. Clothes go round in a circle,
the water goes in straight line… straight
through the holes.

12. CREAM SEPARATOR
• Cream separators are used to remove
the fat content of various products.
• A separator is high speed spinner and
acts on the principal of centrifuge
machines
. The bowl spins at high speed, pushes
lighter contents (cream/ butterfat) inward
and heavier contents outward.
• Skimmed milk (denser than cream) is
collected at outer wall
• The cream is pushed towards center and
collected through pipe.