A particle in a sound wave obeys

PHYSICS · Single correct · A Level · Physics · Waves · Waves

Problem

y(t)=A\sin(\omega t+\phi)

. Its displacement–time graph crosses the equilibrium position at

t=0

while moving toward negative displacement (the slope is negative at that instant). The phase constant

\phi

is (a)

0

(b)

-\dfrac{\pi}{2}

(c)

\pi

(d)

\dfrac{\pi}{2}