physics
posted by kelly .
If the rotational speed of each wheel is 9 revolution per second, what are the tangential speeds of a point on the rim of each wheel?
Note: Wheels spin independently with equal rotation speeds
Diameter of Wheel A: 24
Diameter of Wheel B: 12

9 rev/sec = 18 pi radians/sec. That is called tha angular speed, and usually has a symbol omega. Here, we often use w.
You need to provide a dimension along with the "diameter" number.
Multiply half the diameter (the radius) by the angular speed in radians per second to get the tangential speed.
Tangential speed = w*R 
ok, i tried that and it's still giving me the wrong answer.
On one of the hints it says path/time. I'm so lost, haha 
Tangential speed= 18pi X .24
Tangential speed= 18pi X .12