# Angular Velocity of the Spinning Earth!

1. Oct 24, 2007

### Mr. Sinister

1. The problem statement, all variables and given/known data
The angular velocity of the spinning earth is approximately......
or none of the above
I am new at this forum as of today! I hope that somebody could show me how I should even begin this! I have no idea!

2. Relevant equations

3. The attempt at a solution

2. Oct 24, 2007

### hage567

How long does it take the earth to make 1 revolution?

3. Oct 24, 2007

### Mr. Sinister

It should be 365 days.

4. Oct 24, 2007

### Mr. Sinister

Wait that's around the sun.

5. Oct 24, 2007

### hage567

How many hours are in a day?

6. Oct 24, 2007

### Mr. Sinister

24 hours in a day.

7. Oct 24, 2007

### hage567

OK, you've already stated how many radians are in 1 revolution. So what do you think you should do now? What's angular velocity mean?

8. Oct 24, 2007

### Mr. Sinister

It is the rate of change of angular position. So...... The rate of change must be hmmm... I thought I had it.

9. Oct 24, 2007

### Mr. Sinister

Could the position be 1 revolution and the rate of change 24hrs.?

10. Oct 24, 2007

### hage567

Yes, you know it goes through 1 revolution in 24 hrs.

11. Oct 24, 2007

### Mr. Sinister

Do I put those numbers into an equation?

12. Oct 24, 2007

### hage567

Well yes you could do it that way. $$\omega = \frac{\Delta\theta}{\Delta t}$$

revolutions/hr is a way of stating angular velocity. Look at the units the answers are given in. What do you need to do to get those?

13. Oct 24, 2007

### Mr. Sinister

Well, I believe that there is 2pi radians in a circle. That equation is the change in the angle over the change in time right? I don't know if this info even helped me?

14. Oct 24, 2007

### Mr. Sinister

I am very grateful for your help! This is great considering the tutor room where I go on campus is insanely full with only one tutor per 30 students!

15. Oct 24, 2007

### hage567

Yes there are 2pi radians in a one revolution. The answer is asking for units of radians/hr. You now have everything you need. Your angular velocity is then going to be (2*pi radians)/(24 hrs) which is the change in angle over time, like you say. So what number do you get when you put that into your calculator?

16. Oct 24, 2007

### hage567

You're welcome. Hopefully I'm being helpful.

17. Oct 24, 2007

### Mr. Sinister

18. Oct 24, 2007

### Mr. Sinister

You were very helpful! Do you get paid for helping people? Or is it out of pure kindness? I've noticed that there is alot of homework helpers in the staff section.

19. Oct 24, 2007

### hage567

I'm glad I could help. We do this on our own time for fun.

20. Oct 24, 2007

### Mr. Sinister

Wow!!! That's Awesome!!! Thanks Again!!! I'll be back for sure at a later day!!!