Physics
posted by Victor .
Could someone please help me with this question. Thank you
The person makes a spin through the air, increasing the angular velocity from 3.0 to 5.0 rev/s while rotating through 1/2 revolution. How much time does this it take ?

wfinal^2=winitial^2+ 2*angacceleration*displacement
displacement is PI radians
Wf=2PI*5rad/sec wi= 2PI*3 rad/sec
solve for angular dcceleration,then
angacceleration= (wfwi)/time
and solve for time. 
Im lost is there anyway you can solve this question for me? I know I should try by myself but I get ridiculous answers that defently do not make sense. I know how to solve for Wf which is .5235 and Wi .314159 but then Im lost