It is my understanding that the centrifigul force is not a real force, but the centripetal forces makes you think that there is due to an accelerating inward. When spinning a ball with a string in circles, the centrifigul force makes you think that the ball is trying to fly outward due to the tension in the string, yet the tension is due to the string/force pulling the ball inward. If this is so, why is the earth slightly flattening in the direction of its spin?
2006-06-24 15:57:41 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
You are quite right (and others quite wrong) - centrifugal force is not real.
Circular motion requires an inward (centripetal) force towards the centre of motion. Take that inward force away and object just carry on in a straight line with the velocity they had when the force was removed.
Now for the spinning Earth think about where that force comes from. Its main source is gravity (think about it, it does not take a lot of force to pull bits of soil apart). And the force due to gravity at the surface of the Earth is more or less constant.
But at the equator, the force needed to keep the surface rotating and not flying into space is higher than it is at the poles, because the radius from the axis is larger. But the force or gravity is the same. So gravity can't hold things in quite as close. So the Earth tends to bulge in its middle.
2006-06-24 22:44:48 · answer #1 · answered by Epidavros 4 · 1⤊ 0⤋
You have captured the confusion many people have about "centrifugal force" beautifully in your question. It is true that the only real force on a ball on a string going in a circle is the inward centripetal tension force pulling on the ball. That force and that force alone makes the ball accelerate toward the center of the circle and as a result the ball follows a circular path.
Now imagine not a string but a spring or rubber band tied to the ball. If you whip the ball around faster, the rubber band will stretch out more. That's because a larger inward force is required to produce the larger acceleration that exists when the ball is moving faster, and the rubber band or spring has to stretch to create that larger pull.
2006-06-24 23:19:50 · answer #2 · answered by Steve H 5 · 0⤊ 0⤋
Centrifugal force is real.
Here's a good example. Get a gasoline powered RC car or a fullsize motorcycle. Now set the back wheels so the vehicle cannot move and floor it. Think of the tires as Earth, and watch as they expand.
On my quad, I have cut front fenders. If I let some of the air out of my front tires, I can watch as they seem to inflate themselves when I gain speed.
I don't understand the flattening of the Earth, as it is spinning relatively slowly. The tires on the car/bike have to be moving extremely fast to get a result.
2006-06-24 23:03:56 · answer #3 · answered by jeff_is_sexy 4 · 0⤊ 0⤋
The Earth flattens at the poles as the Earth rotates. Then at the equator it bulges outward a little bit. This is caused by the Earth's rotational force. This is basically the same with all of the planets, the planets moons as well as our sun in our solar system.
2006-07-01 05:27:24 · answer #4 · answered by Anonymous · 0⤊ 0⤋
It's semantics. you are trying to go in a straight line and the string is holding you back, but on the earth, there is no "string".
The matter is being pushed out by "centrifugal" force and held in by gravity so the balance at the equator allows for more bulging than nearer the poles.
2006-06-24 23:15:44 · answer #5 · answered by Anonymous · 0⤊ 0⤋
centrifigul force is real
The earth is in fact not a perfect sphere. It is flat on the top and bottom and wider at the equator. This is due to centriful force. The force causes more mass to go towards the outer parts, ie, the equator and less at the top.
2006-06-24 23:36:20 · answer #6 · answered by Anonymous · 0⤊ 0⤋