Linear Speed at South Pole Antarctica

[sphyics]

What would be the linear speed of body in Antartica standing on a south pole.

 

[Taftarat]

What would be the linear speed of body in Antartica standing on a south pole.

depends on reference point. earth? sun? solar system? galaxie?

 

[sphyics]

depends on reference point. earth? sun? solar system? galaxie?

consider Earth as reference point.

 

[JaredJames]

consider Earth as reference point.

Linear speed implies you are moving in a straight line. You are not.

You would be moving with rotational velocity (whether in reference to the Earth or Sun).

Of course this is largely semantics.

With the Earth as your reference point, you would be rotating on the spot but that is all. Like a ballerina in a music box.

 

[sphyics]

Linear speed implies you are moving in a straight line. You are not.

You would be moving with rotational velocity (whether in reference to the Earth or Sun).

Of course this is largely semantics.

With the Earth as your reference point, you would be rotating on the spot but that is all. Like a ballerina in a music box.

yes i agree, hence i had an intuition, the answer as 360 degrees per day from the options given A) 7x10^-5rad/s; B)360 degrees per day c)Both (A) &(B) D) 0

but I'm trying to put it mathematically :)

 

[JaredJames]

yes i agree, hence i had an intuition, the answer as 360 degrees per day from the options given A) 7x10^-5rad/s; B)360 degrees per day c)Both (A) &(B) D) 0

but I'm trying to put it mathematically :)

Well work out how many degrees are per second (360 / (24*60*60)).

Then convert that value to rad/s, see if it matches A.

Problem is, that gives you a rotational speed, not strictly a linear one (bit of ambiguity in the question for my liking). So I'd say the answer is D.

 

[sphyics]

Well work out how many degrees are per second (360 / (24*60*60)).

Then convert that value to rad/s, see if it matches A.

approximately ... its 7.2x10^-5rad/s {sorry for that i made a calculation error earlier.}

Problem is, that gives you a rotational speed, not strictly a linear one (bit of ambiguity in the question for my liking). So I'd say the answer is D.

how i discarded the answer Zero (i too had the same notion first) velocity may be zero as displacement is zero but not speed...

& the other one ...

what will be the change in momentum if a particle moves from one point to its diametrically opposite.

 

[JaredJames]

Please note the difference between an objects linear velocity and angular velocity:

http://www.algebralab.org/lessons/lesson.aspx?file=trigonometry_triganglinvelocity.xml

Your whole body (and the Earth) will have one angular velocity (which comes from 360 degrees per day).

But each point on the Earths surface at a different radius will have its own linear velocity.

On the south pole, your left arm will have a higher linear velocity than your head.

At a point infinitely small, directly on the south pole you would have zero linear velocity.

So my point is that unless you know which part of your body they are referring to, you can't give a linear velocity. Only an angular one.

 

[sphyics]

Please note the difference between an objects linear velocity and angular velocity:

http://www.algebralab.org/lessons/lesson.aspx?file=trigonometry_triganglinvelocity.xml

Your whole body (and the Earth) will have one angular velocity (which comes from 360 degrees per day).

But each point on the Earths surface at a different radius will have its own linear velocity.

On the south pole, your left arm will have a higher linear velocity than your head.

At a point infinitely small, directly on the south pole you would have zero linear velocity.

So my point is that unless you know which part of your body they are referring to, you can't give a linear velocity. Only an angular one.

Consider a particle not a body, suppose if the particle was at equator T(Period)=24hrs, then v=r(radius vector)*w(angular velocity)
how to proced with a particle at poles...

 

[JaredJames]

Consider a particle not a body, suppose if the particle was at equator T(Period)=24hrs, then v=r(radius vector)*w(angular velocity)
how to proced with a particle at poles...

The only difference is the radius, and like I said, unless you know the specific part of the body (the radius) then you can't give an answer.

Particle, body, all the same. Assume the outside radius and go with that if you really need to.

 

[sphyics]

The only difference is the radius, and like I said, unless you know the specific part of the body (the radius) then you can't give an answer.
.

its a question from a competitive exam :)

 

[JaredJames]

its a question from a competitive exam :)

And...

It doesn't change the fact you need a radius to have a linear velocity.

If you don't have a radius and assume an infinitely small point on the south pole, the radius is then 0 (distance from centre of rotation), plug that into your equation and your linear velocity is 0. Hence D being the correct answer.