A basketball rolls around a 0.23 meter rim and is able to complete a revolution in 0.3 seconds. What is the velocity of the basketball on the rim? I know how to solve this but don't know if the diameter is .23 or the radius is .23

Please help me as another question relies on this answer

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.

The electronic structure or chlorine is 2.8.7 what is the electronic structure of fluorine?