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rohit199622
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I know that radial force comes into the play but the direction of gravity (9.8) is also the same as radial acceleration so instead it should increase on equator
Should it? In which direction is the radial acceleration oriented with respect to the earth? Is this in the same direction as gravitational acceleration?rohit199622 said:I know that radial force comes into the play but the direction of gravity (9.8) is also the same as radial acceleration so instead it should increase on equator
Nugatory said:There's an interesting picture, along with an explanation, at http://www.universetoday.com/26775/gravity-of-the-earth/.
A.T. said:Are these anomalies the deviations from a constant g value for the entire Earth, or from a local g value that already takes the rotation into account?
rohit199622 said:Okay so .. Whenever we rotate something like stone attached a thread or anything we give centripetal force so that it doesn't go away
but in case of rotation due to Earth there is no centripetal force being provided gravity is a different force all together this is how I understand it ..I got confused just because there was a formula thing in my textbook to calculate gravity change at equator and is my explanation right ?
This formula is for calculating the value of g at altitude h above the surface of the earth.In circular motion, the tangential velocity v = r ω, where r is the radius of the circular path of motion and ω is the angular velocity.Delta² said:To make it crystal clear can someone give the formula of the radial acceleration? I know the formula for the gravitational acceleration is [itex]g=G\frac{M_{earth}}{(R_{earth}+h)^2}[/itex]
SteamKing said:The centripetal acceleration at the equator = r ω2 = 6 371 000 * [7.272 × 10-5]2 = 0.034 m/s2
Since the value of g is approximately 9.81 m/s2, one can see that the rotation of the Earth introduces a small change in the value of g.
It's not due to a reaction from the earth; it's due to our bodies (or whatever) wanting to continue traveling in a straight line as the Earth turns beneath our feet.Delta² said:Just to clarify it a bit more, this small change is a phenomenical change in g, its not because rotation produces some sort of anti gravitational field (just saying now), its because thiss 0.034m/s^2 goes as centripetal acceleration and what is left 9,81-0,034 is what we feel as the reaction force from the surface of the earth. is that correct?
That is correct in the non-rotating frame.Delta² said:Just to clarify it a bit more, this small change is a phenomenical change in g, its not because rotation produces some sort of anti gravitational field (just saying now), its because thiss 0.034m/s^2 goes as centripetal acceleration and what is left 9,81-0,034 is what we feel as the reaction force from the surface of the earth. is that correct?
A.T. said:That is correct in the non-rotating frame.
In the co-rotating frame you have an inertial centrifugal force, due to rotation of the frame, not of the Earth. But I wouldn't call that an "anti gravitational field", because it acts away from the axis, not away from the center. So it is opposite to gravity only on the equator.
http://www.regentsprep.org/regents/physics/phys06/bcentrif/centrif.htmTom_K said:You said the http://www.regentsprep.org/regents/physics/phys06/bcentrif/centrif.htm
In the inertial frame where everything is rotating. Not in the co-rotating frame where everything is staticTom_K said:Part of the gravitational acceleration is needed to keep everything rotating with the surface of the earth...
Gravity decreases at the equator because of the centrifugal force caused by the Earth's rotation. This force counteracts the pull of gravity, resulting in a weaker gravitational force at the equator compared to the poles.
The Earth's shape, specifically its oblate spheroid shape, also contributes to the decrease in gravity at the equator. This shape causes the equator to be farther away from the center of the Earth, resulting in a weaker gravitational pull.
Yes, the decrease in gravity at the equator does affect weight. Objects weigh slightly less at the equator compared to the poles due to the weaker gravitational pull.
Altitude does not have a significant effect on gravity at the equator. The decrease in gravity at the equator is primarily due to the Earth's shape and rotation, not altitude.
Gravity is different at different latitudes because of the Earth's shape and rotation. The Earth's oblate spheroid shape and rotation result in a weaker gravitational force at the equator compared to the poles.