# More Spring oscillation

[SOLVED] More Spring oscillation

## Homework Statement

A 2.20 kg mass is attached to a spring and placed on a horizontal, smooth surface. A horizontal force of 17.6 N is required to hold the mass at rest when it is pulled 0.200 m from its equilibrium position (the origin of the x axis). The mass is now released from rest with an initial displacement of xi = 0.200 m, and it subsequently undergoes simple harmonic oscillations. Calculate the maximum speed of the mass.

Spring constant is 88.0 N/m
Oscillation frequency is 1.00 Hz

## Homework Equations

This is pretty much the problem; i dont know what equation to use to get the max velocity

## The Attempt at a Solution

Ive been messing around with V = -AwSin(wt) but i cant fathom how to get amplitude..

Hootenanny
Staff Emeritus
Gold Member
HINT: The amplitude is given in the question.

mkay, well the only thing i can see close to amplitude is Xi. But if thats amplitude, then all i have left to find is time..

Hootenanny
Staff Emeritus
Gold Member
mkay, well the only thing i can see close to amplitude is Xi. But if thats amplitude, then all i have left to find is time..
xi is indeed the amplitude. However, there is no need to consider the amplitude, period, angular velocity etc. This problem can be trivially solved using conservation of energy.

Ek = 1/2 mv^2, but i dont have kenetic energy...

Hootenanny
Staff Emeritus
Gold Member
Ek = 1/2 mv^2, but i dont have kenetic energy...
No you don't have the kinetic energy, but you can work out the initial potential energy...

Ep= 1/2 kX^2 <-- is this the equation you're referring to?

Hootenanny
Staff Emeritus
Gold Member
Ep= 1/2 kX^2 <-- is this the equation you're referring to?
Indeed it is, and since energy is conserved you can use this to determine the velocity of the mass at any point.

No problem 