A mass is attached to a spring of constant

PHYSICS · Single correct · CBSE · Physics · Oscillations · Oscillations

Problem

0.20\,\text{kg}

mass is attached to a spring of constant

80\,\text{N\,m}^{-1}

. The total mechanical energy of the system is

0.32\,\text{J}

. At

t=0

the displacement is

+0.060\,\text{m}

and the mass is moving toward the equilibrium position. If the motion is written as

x(t)=A\cos(\omega t+\phi)

, which of the following is the correct value of

\phi

(in radians,

-\pi<\phi\le\pi

)? (a)

-0.84

(b)

0.84

(c)

0.74

(d)

2.30