Question

In a horizontal spring-mass system, mass m is released after being displaced towards right by some distance at t = 0 on a frictionless surface. The phase of the simple harmonic motion in radian when it is first time passing through the equilibrium position is equal to:

• A. π /2
• B. π
• C. 3π/2
• D. 0

Answer 1

Answer: (B)

π

Answer 2

Phase of the motion is (ωt + φ).

Using x = A sin (ωt + φ)

and v = Aω cos(ωt + φ)

for conditions at t = 0 → x = A and v = 0 then φ = π/2

When it passes equilibrium position for the first time t = T/4

Phase = radians