Help on the freaking simple question that is ****ing me off at the moment

Hi guys, here is one question that I can't get for some reason, I just
can't. I come close to it, but everytime I am by 300km/hr off. Anyhow here
is the question and could someone please tell me how it's done.

"Derive the equation from which you could calculate speeds of someone on the
surface of the Earth, depending on their latitude. The equation will depend
on person's latitude, (Q), the radius of the Earth, (Re), and the period of
rotation, (T). ( I tried it, but nothing.) (Hints: the speed of a person on
a Northpole is 0 km/hr and speed of a person on the Equator is 1650 km/hr)

"Zarkovic" wrote in
news:ye9ab.8990$CU3.7779@pd7tw3no:

Hi guys, here is one question that I can't get for some reason, I just
can't. I come close to it, but everytime I am by 300km/hr off. Anyhow
here is the question and could someone please tell me how it's done.

"Derive the equation from which you could calculate speeds of someone
on the surface of the Earth, depending on their latitude. The equation
will depend on person's latitude, (Q), the radius of the Earth, (Re),
and the period of rotation, (T). ( I tried it, but nothing.) (Hints:
the speed of a person on a Northpole is 0 km/hr and speed of a person
on the Equator is 1650 km/hr)




Speed = cosine(latitude)*1650

Martin Lewicki

"Zarkovic" wrote in
news:ye9ab.8990$CU3.7779@pd7tw3no:

Hi guys, here is one question that I can't get for some reason, I just
can't. I come close to it, but everytime I am by 300km/hr off. Anyhow
here is the question and could someone please tell me how it's done.

"Derive the equation from which you could calculate speeds of someone
on the surface of the Earth, depending on their latitude. The equation
will depend on person's latitude, (Q), the radius of the Earth, (Re),
and the period of rotation, (T). ( I tried it, but nothing.) (Hints:
the speed of a person on a Northpole is 0 km/hr and speed of a person
on the Equator is 1650 km/hr)




Speed = cosine(latitude)*1650

Martin Lewicki

"Zarkovic" wrote in message
news:ye9ab.8990$CU3.7779@pd7tw3no...
Hi guys, here is one question that I can't get for some reason, I just
can't. I come close to it, but everytime I am by 300km/hr off. Anyhow here
is the question and could someone please tell me how it's done.

"Derive the equation from which you could calculate speeds of someone on
the
surface of the Earth, depending on their latitude. The equation will
depend
on person's latitude, (Q), the radius of the Earth, (Re), and the period
of
rotation, (T). ( I tried it, but nothing.) (Hints: the speed of a person
on
a Northpole is 0 km/hr and speed of a person on the Equator is 1650 km/hr)

Assuming the earth is perfectly round:

Speed = [2 * Pi * Re * Cosine(Q)] / T

How it is done? just find the perimeter of the circle described by the
person as it rotates for the duration of the period T. Then divide that
perimeter by the period T to find the speed.

Am I doing your homework?

Guillermo

"Zarkovic" wrote in message
news:ye9ab.8990$CU3.7779@pd7tw3no...
Hi guys, here is one question that I can't get for some reason, I just
can't. I come close to it, but everytime I am by 300km/hr off. Anyhow here
is the question and could someone please tell me how it's done.

"Derive the equation from which you could calculate speeds of someone on
the
surface of the Earth, depending on their latitude. The equation will
depend
on person's latitude, (Q), the radius of the Earth, (Re), and the period
of
rotation, (T). ( I tried it, but nothing.) (Hints: the speed of a person
on
a Northpole is 0 km/hr and speed of a person on the Equator is 1650 km/hr)

Assuming the earth is perfectly round:

Speed = [2 * Pi * Re * Cosine(Q)] / T

How it is done? just find the perimeter of the circle described by the
person as it rotates for the duration of the period T. Then divide that
perimeter by the period T to find the speed.

Am I doing your homework?

Guillermo

Ahhh man, thanks guys. For some reason I turned my sphere around and I used
for equator speed cos (90) which equals to 0 , but I should have used cos
(0) instead. Sorry for the mix up, and thanks once again to both of you.

Ahhh man, thanks guys. For some reason I turned my sphere around and I used
for equator speed cos (90) which equals to 0 , but I should have used cos
(0) instead. Sorry for the mix up, and thanks once again to both of you.

"Zarkovic" wrote in message
news:ye9ab.8990$CU3.7779@pd7tw3no...
Hi guys, here is one question that I can't get for some reason, I just
can't. I come close to it, but everytime I am by 300km/hr off. Anyhow here
is the question and could someone please tell me how it's done.

"Derive the equation from which you could calculate speeds of someone on
the
surface of the Earth, depending on their latitude. The equation will
depend
on person's latitude, (Q), the radius of the Earth, (Re), and the period
of
rotation, (T). ( I tried it, but nothing.) (Hints: the speed of a person
on
a Northpole is 0 km/hr and speed of a person on the Equator is 1650 km/hr)


I don't know what the radius of the earth would have to do with it. Your
speed depends on your perpendicular distance from the earth's axis (as
though the latitude you are at is the circumference of a wheel that is
spinning on the axis).

R

"Zarkovic" wrote in message
news:ye9ab.8990$CU3.7779@pd7tw3no...
Hi guys, here is one question that I can't get for some reason, I just
can't. I come close to it, but everytime I am by 300km/hr off. Anyhow here
is the question and could someone please tell me how it's done.

"Derive the equation from which you could calculate speeds of someone on
the
surface of the Earth, depending on their latitude. The equation will
depend
on person's latitude, (Q), the radius of the Earth, (Re), and the period
of
rotation, (T). ( I tried it, but nothing.) (Hints: the speed of a person
on
a Northpole is 0 km/hr and speed of a person on the Equator is 1650 km/hr)


I don't know what the radius of the earth would have to do with it. Your
speed depends on your perpendicular distance from the earth's axis (as
though the latitude you are at is the circumference of a wheel that is
spinning on the axis).

R

"Ron Miller" wrote in message
...

"Zarkovic" wrote in message
news:ye9ab.8990$CU3.7779@pd7tw3no...
Hi guys, here is one question that I can't get for some reason, I just
can't. I come close to it, but everytime I am by 300km/hr off. Anyhow
here
is the question and could someone please tell me how it's done.

"Derive the equation from which you could calculate speeds of someone on
the
surface of the Earth, depending on their latitude. The equation will
depend
on person's latitude, (Q), the radius of the Earth, (Re), and the period
of
rotation, (T). ( I tried it, but nothing.) (Hints: the speed of a person
on
a Northpole is 0 km/hr and speed of a person on the Equator is 1650
km/hr)


I don't know what the radius of the earth would have to do with it. Your
speed depends on your perpendicular distance from the earth's axis (as
though the latitude you are at is the circumference of a wheel that is
spinning on the axis).
Because that perpendicular distance, is cos(Q)*Re...
You either have to have the radius of the Earth, or another way of working
out that perpendicular distance.

Best Wishes