Calculating Tangential and Angular Velocity?

[Bananarama]

Hello, I have been set a question for homework that ask's "calculate the tangential velocity (v) and the angular velocity (omega) of our moons orbit". The teacher has lead me to believe that tangential velocity is just regular velocity? is this correct?. I understand what angular velocity is, but i do not understand how to calculate it, using the values given. Any help, or some kind of starting point would be greatly appreciated.



We have been given the values of:
distance from Earth to Moon (centre - centre) = 3.844 E8 metres
Moon's Sidereal period = 27.322 days
Moon's synodic period = 29.53 days
Radius of Earth (Re) = 6.378 E6 metres
Radius of Moon (Rm) = 1.738 E6 metres
(I use E to represent X 10 to the power of)



I have attempted tp use omega = d(theta) / dt, which gave me a result of 152.502 E-6 rad/s. I used 360 as theta and 27.322 days as the time (2360620.8 seconds)

 

[Dick]

If you want an angular velocity in rad/sec, shouldn't you use total angle=2*pi, rather than 360 degrees? Or did you want it in degrees per second?

 

[Bananarama]

Oops, i forgot that it should be 2*pi.

I do need it in rad/sec. Because the formula i was going to use for tangential velocity is v = r*angular velocity ( I am not even sure if that formula is correct). But the angular velocity is measured in rad/sec.

 

[Sammm#121212]

What does the * mean?? I am doing that exact question and i don't understand a thing?? please help and when you say 2*pi does that mean 2 X 3.1415... which = 6.283... and X means multiplied??

 

[Dick]

What does the * mean?? I am doing that exact question and i don't understand a thing?? please help and when you say 2*pi does that mean 2 X 3.1415... which = 6.283... and X means multiplied??

Sure '*' just means multiply.