Simple harmonic motion question

[i_heart_you]

Simple harmonic motion question!

Homework Statement

A mass undergoing simple harmonic motion has a displacement of X = 0.5 m and V = 4 m/s at one time and x=.25 and V = -8. what is the period of this oscillation?

Homework Equations

X(t) = Acos (wt + phi)
V(t) = -Awsin (wt + phi)

The Attempt at a Solution

 

[tiny-tim]

Hi i_heart_you!

(have a phi: φ and an omega: ω )

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