பேருந்துகளை கவிழ்க்கும் அறிவியல்! Centripetal and Centrifugal Force
6 Minutes
Centripetal and centrifugal force explained for students, from vehicle toppling and banked roads to rocket launches. A Tamil science lesson.
- Swirling a container with a stone to show circular forces
- Why banked roads and tilting trains prevent overturning
- Using Earth's rotation to launch rockets near the equator
What this lesson teaches
Centripetal force is the inward pull (maiya nokku visai) that keeps an object moving in a circle, while centrifugal force is the outward push (maiya vilakku visai) felt by that turning object.
Forces in circular motion
When an object is swung in a circle, like a container with a stone inside tied to a string, an inward force acts along the string toward the center. This inward pull is centripetal force. At the same time, the stone inside feels pushed toward the outside of the turn, which is centrifugal force. A person inside a car turning sharply to the left feels pushed toward the right for the same reason.
Why turning vehicles topple
- Friction between tyres and the road acts as centripetal force to keep a vehicle on a curved path.
- When a bus or truck turns quickly, centrifugal force pushes the vehicle and everything inside outward.
- If centrifugal force exceeds the friction holding the tyres or the load, the vehicle tilts or flips over.
- In an overcrowded bus, passengers are thrown toward the outer side, shifting the total weight outward and overturning the bus.
Engineering roads and trains
To prevent fast vehicles from overturning, engineers build curved highway roads with an inward slope called banking of roads. Railway tracks at curves are also tilted so high-speed trains do not topple outward. For bullet trains travelling at 300 kilometres per hour in Japan, tracks cannot be tilted too steeply because slow or stopped trains would fall inward. Instead, engineers use air suspension systems to tilt the train body itself during sharp turns.
Launching rockets near the equator
- In sports like the hammer throw, spinning an object faster before releasing it gives it higher centrifugal force and sends it much farther.
- Earth rotates once a day, moving places near the equator across 40,000 kilometres while places near the North Pole move only 10 kilometres.
- Because the equator moves much faster, rockets launched near it receive a larger outward centrifugal boost from Earth's rotation.
- Space centres in Sriharikota and Thiruvananthapuram use this boost so rockets reach high speeds using far less fuel.