Centrifugal Force

Here are some examples of centrifugal force in real life.

• When the wheels of a vehicle rotate on a dirty wet road, they scatter mud around them due to the centrifugal force.
• Earth spins about its axis, thus creating a centrifugal force. A person standing on the surface experiences this force in a direction away from the axis. Earth’s gravitational force keeps objects pinned on the surface.
• A bucket of water rotating in a vertical plane does not spill water because it is pinned to the bottom by centrifugal force.
• Children sitting on a merry-go-round experience an outward pull as it rotates about its vertical axis.
• Centrifugal force results in the bulging of the Earth at the equator and flattening at the poles.
• A top spinning on its axis experiences a centrifugal force.
• A ball attached to a string experience centrifugal force when it twirls

How Does Centrifugal Force Exist in Driving

Centrifugal force is often associated with a vehicle that takes a turn around a curve. When a car goes around a curve, the passengers feel a force directed away from the curve’s center of curvature due to inertia. This force is the centrifugal force. However, for someone outside the car, they would see a different force – the one that is directed toward the center. It is called centripetal force.

How to Find the Centrifugal Force

We use Newton’s laws of motion to measure the centrifugal force. Suppose an object of mass m is rotating in a circular path of radius r with a velocity v. Then, the centrifugal force F_C is,

F_C = mv²/r

Unit: Newtons or N

The importance of the centrifugal force is its wide range of applications. Here are some of them.

• Centrifuge: A centrifuge is a device that spins test tubes containing particles suspended in liquids. As the device whirls, the heavier particles settle down at the bottom due to centrifugal force. The centripetal acceleration is measured as a fraction of the acceleration due to gravity g. The force is known as relative centrifugal force (RCF).
• Washing Machine: The cylindrical tub of a washing machine spins fast enough to force the water out of the clothes. Centrifugal force forces water to pass through the perforations on the tub’s walls.
• Artificial Gravity: Artificial gravity can be created in space by rotating a space station. By adjusting a few space station parameters, such as the radius and rotation rate, it is possible to create a force on the outside walls that equals gravity.