Question

Equation of SHM of particle is given by x = sinπ (t + 1/3), then velocity at t = 1 sec. is 

(1) -π/2

(2) π

(3) -π/3

(4) -π/4

Answer 1

Correct option is (1) -π/2

v = dx/dt = πcosπ(t+ 1/3)

v at t = 1 = πcosπ(1+ 1/3)

= πcos(π + π/3)

= -πcos π/3

= -π/2