physics help
posted by rory on .
a particle moves uniformly around the circumference of a circle whose radius is 8 cm with a period of pi/20 s. the angular velocity w of the particle is
a. 2.5 rad/s
b. 3.2 X 10^2 rad/s
c. 40 rad/s
d. 7.9 rad/s
e. 96 rad/s
please explain
thanks!

Period is the reciprocal of frequency.
angular frequency is 2PI*frequency 
i didn't get that....

frequency=1/Period