1 ) It takes 23 hours 56 minutes and 4 seconds for the earth to make one revolution (mean sidereal day). What is the angular speed of the earth?
(in rad/s) 7.29×10-5 rad/s

2) Assume the earth is spherical. Relative to someone on the rotation axis, what is the linear speed of an object on the surface if the radius vector from the center of the earth to the object makes an angle of 49.0° with the axis of rotation. The radius of the earth is 6.37×103 km.
(in m/s) 3.51×102 m/s

3) What is the acceleration of the object on the surface of the earth in the previous problem?
(in m/s^2)

what can I do for number 3, I;m done with 1 and 2
I tried to use a = v^2/r
but I faild :(

1. Right!

2. Right!

3. I think that you have to get the acceleration relative to the centre of the Earth.

What you probably got is the acceleration towards the axis of rotation, not the centre of the Earth.

I'm not sure, but I got 0.0256 m/s^2 relative to the axis of rotation.

Maybe it's asking for the acceleration towards the centre of the Earth?

Your answer is right ! How did u got it- calculate it -?
Thanks you are amazing.

I used v^2/r :confused:

I thought you used that..

\frac{v^2}{r} = \frac{351^2}{6.37\times10^3 \times 1000} = 0.0256 m/s^2

Ah OK , yeah same thing :)
Thaaaaaaaanks ;)

I just put 10^9 instead of 10^6
haha