# trigonometry

posted by .

assuming that Earth's radius is 6400 km, find the linear velocity of Quito, Equador, a city on the equator. (Use pi=3.1416 and 1.6 km=1 mile).

• trigonometry -

I guess we are to do miles per hour ?

v = omega * r
omega = 2 pi /24 hr
r = 6.4*10^3 km (1 mile/1.6 km) = 4,000 miles
so
v = 4000 miles (2 pi/ 24 hr)
=3333 miles/ hour

• trigonometry -

(2 pi * 6400 km)/(24 hours)

That will give you the answer in km/h. Divide by 1.6 for miles per hour.

Actually, a better conversion factor with five significant figures is 1.6093 km/mile

It makes no sense to have five significant figures for pi and only two for the km-to-miles factor

• trigonometry -

my choices are
2094.4 mph
209.4 mph
1047.2 mph
104.7 mph

• trigonometry -

LOL - the textbook writer is using a calculator with pi on it but not the unit conversions :)

• correction -

v = 4000 miles (2 pi/ 24 hr)
=1047.2 miles/ hour

• trigonometry -

thnks

## Similar Questions

Earth turns on its axis approximately once every 24 hours. The radius of Earth is 6.38 X 10^6 m. a.) If some astronomical catastrophe suddenly brought Earth to a screeching halt (a physical impossibility as far as we know), with what …
2. ### physics??

The earth rotates once per day about an axis passing through the north and south poles, an axis that is perpendicular to the plane of the equator. Assuming the earth is a sphere with a radius of 6.38 x 106 m, determine the centripetal …
3. ### physics

A communications satellite is in a synchronous orbit that is 3.00 107 m directly above the equator. The satellite is located midway between Quito, Equador, and Belem, Brazil; two cities almost on the equator that are separated by a …
4. ### physics

The earth rotates once per day about an axis passing through the north and south poles, an axis that is perpendicular to the plane of the equator. Assuming the earth is a sphere with a radius of 6.38 x 106 m, determine the centripetal …
5. ### physics

I am so confused How fast (in km/hr) must a plane fly along the Earth's equator so that the Sun stands still relative to the passengers. The radius of the Earth is 6400 km
6. ### physics

A communications satellite is in an orbit that is 3.1 multiplied by 107 m directly above the equator. Consider the moment when the satellite is located midway between Quito, Equador, and Belem, Brazil; two cities almost on the equator …
7. ### maths

the radius of our plant earth is about 6400 km how far is it around the equator
8. ### physics

Early skeptics of the idea of a rotating Earth said that the fast spin of Earth would throw people at the equator into space. The radius of Earth is about 6400 km. Show why this objection is wrong by determining the following information. …
9. ### Astronomy

The Hubble Space Telescope orbits at an altitude of 600 km above the Earth's surface. Assuming it is in a stable circular orbit, what is its velocity?
10. ### Physics

A geostationary satellite orbits the Earth in such a manner that it is always directly above the same point on the equator as the Earth rotates. Assuming that this orbit is circular, what is its radius?

More Similar Questions