Find the angular speed of a point on the earth surface. That is all that is given, assume that Radius is 6400km. how do I set this up.
Hello, Brndo4u!
There is either too much information or insufficient information.
Find the angular speed of a point on the Earth's surface.
Assume that radius of the Earth is 6400 km.
Every point on the Earth, except the two poles, turns though 360° every 24 hours.
. . Hence, the point moves: .$\displaystyle \frac{360}{24} \:=\:15\text{ degrees per hour.}$
And the radius of the Earth is irrelevant.
If the speed is to be in kilometers per hour,
. . we should have been given the latitude of the point.
Assuming that point is on the Equator,
. . the circumference is: .$\displaystyle 2\pi\cdot6400 \:\approx\:40,\!212.4$ km.
Then the point moves at: .$\displaystyle \frac{40,\!212.4}{24} \:\approx\:1675.5$ km/hr.