# Geography problem

• Aug 10th 2011, 06:14 AM
explodingtoenails
Geography problem
The latitude of Jackson, Mississippi is 32degrees17minutes N, and the latitude of St. Louis, Missouri, is 38degrees37minutes N. The radius of Earth is about 4000 miles.

a) About how far apart are the two cities?

b) If Earth makes one revolution every 24 hours, what is the linear velocity of a point near the equator?

Having severe trouble over here. For a) I know the difference of their latitudes is 6degrees20minutes but I don't know what to do from there.

And for b) I did (4000)(2pi/24). I don't know if it's right though.
• Aug 10th 2011, 08:00 AM
earboth
Re: Geography problem
Quote:

Originally Posted by explodingtoenails
The latitude of Jackson, Mississippi is 32degrees17minutes N, and the latitude of St. Louis, Missouri, is 38degrees37minutes N. The radius of Earth is about 4000 miles.

a) About how far apart are the two cities?

Use proportions:

$\displaystyle \dfrac{\overbrace{2\pi\cdot 4000\ mi}^{circvumference\ of\ Earth}}{360^\circ} = \dfrac d{6^\circ 20'}$

Solve for d.

Quote:

b) If Earth makes one revolution every 24 hours, what is the linear velocity of a point near the equator?

Having severe trouble over here. For a) I know the difference of their latitudes is 6degrees20minutes but I don't know what to do from there.

And for b) I did (4000)(2pi/24). I don't know if it's right though.
Use the definition of $\displaystyle speed = \dfrac{distance}{time}$

$\displaystyle v = \dfrac{\overbrace{2\pi\cdot 4000\ mi}^{length\ of\ equator}}{24\ h}$

The result is in $\displaystyle \frac{mi}h$