Mechanics stuck on a sum on simple harmonic motion:help:

A particle P is moving on a straight line with S.H.M. of period pi/3 s. Its maximum speed is 5 m/s. Calculate the amplitude of the motion and the speed of P 0.2s after passing through the centre of oscillation.

My workings:

T=2pi/w So w=6

x=0, v=5

5^2=6^2(a^2-0) so a=5/6 (matched with book)

t=0.2s

v=-awsinwt=-5/6*6sin (1.2)=4.66

The answer given in book is 1.81.

Somebody help. What did go wrong with this very simple sum?http://static.thestudentroom.co.uk/i...ilies/help.gif