# Genius in physics wanted

#### Nocturn888

Genius in physics wanted!!!

I have this question that i tried to solve for ages now and i still can't figure it out, in other word help would be very much appreciated.

QUESTION: The earth's radius is 6400km. How fast is a point on the equator moving? What is the speed of Beirut at latitude 34º?

The answer in the back of my book says i.) 465.4 m/s, ii.)385.6 m/s.

The question is from the book on advanced physics from Steve Adams and Jonathan Allday (topic 3.1 q.5)

Thank you very much,to who ever it is,that can help me

Related Introductory Physics Homework Help News on Phys.org

#### HMS

Assume that the earth is a perfect sphere

You know the radius of the sphere. Now what is the circumference of the equator, given that it is a circle whose radius is given in the problem? You know how much time it takes for a point in the equator to get back to the same position. It is one day. So the speed of the equator point is the circumference divided by this time.

Coming to the second part, what is the radius of a circle that passes through all latitude 34 points in the earth's surface, including Beirut. Once you calculate this radius by drawing it on paper and using some basic trigonometry , repeat the above method using this radius.

Hope I havent confused you further. Good luck.

As you will realise, it does not require a physics genius to solve this problem.

#### Nocturn888

Thank you very much for your help :)

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