# Centrifugal force question! need help!

1. Dec 7, 2009

### johnq2k7

Calculate the centrifugal acceleration associated with

a.) The rotation of the Earth around its axis, as measured on the equator
b.) The Earth moving around the Earth-Sun centre of mass. Assume the orbit is circular
c._ The Sun moving around the Earth-Sun centre of mass. Same assumption as in b.)

Work shown...

i'm so confused with centrifugal and centripetal acceleration... but this question is asking for 'centrifugal' accel.

for a.) i did a_z= (omega^2)*(x)
where omega= sqrt (G*(M+m))/(r^3))

i don't understand how measure this since it's at the equator

for b.) do i simply use the weight of the earth, earth, and distance from the earth to the sun.. and sub in

for c>0 do i simply use the weight of the sun, earth, and distance from the earth to the sun.. and if so what's the difference

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Dec 7, 2009

### tiny-tim

Hi johnq2k7!
"Centrifugal" just means the opposite of centripetal … it's a daft way of asking the question, like "A rocket is launched into space: what is its speed downwards?"
no, this is geometry, not physics …

you're not asked why is there acceleration (gravity etc), only what is the acceleration …

for that, you only need to know the length of the day and the year (and you can look that up in a diary ), and the distances involved.