A particle executes simple harmonic motion according to the displacement equation y = 10 cos(2πt+π6)cm;, where t is in seconds. The velocity of the particle at t = 16 seconds will be:

Velocity v = dydt = ddt[10 cos(2πt+π6)]                   = -20π sin(2πt+π6) cms-1v(16) = -20(3.14)sin(π3+π6)cms-1    = 62.8 cm s-1(numerically)        [Using sin π2 = 1]        = 0.628 ms-1