Homework Help: Simple Harmonic Motion: Position, Velocity, & Acceleration

1. Apr 21, 2012

hardygirl989

1. The problem statement, all variables and given/known data
A 1.00-kg glider attached to a spring with a force constant 49.0 N/m oscillates on a frictionless, horizontal air track. At t = 0, the glider is released from rest at x = -3.50 cm (that is, the spring is compressed by 3.50 cm).

Find the position, velocity, and acceleration as functions of time. (Where position is in m, velocity is in m/s, acceleration is in m/s2, and t is in s. Use the following as necessary: t.)

2. Relevant equations
x(t)=Acos(ωt+∅)

3. The attempt at a solution
I know that the amplitude is going to be positive 0.035m
Thus, x(t)=0.035cos(ωt+∅)

∴ x(t)=0.035cos(7t+∅)

The only thing I am still confused about is how to find ∅...Can anyone help please and thank you?

2. Apr 22, 2012

azizlwl

Compare with simple Cosine graph y=Cos(θ).
Check what is new function be if it is shifted to the left by certain radian.

3. Apr 22, 2012

hardygirl989

The phase shift for the cosθ would be ∏
∴ x(t)=0.035cos(7t+∏)

Thank you!

SOLVED.