Oscillator Problem Maximum speed & amplitude

[jjd101]

Homework Statement

A 800g oscillator has a speed of 120.0 cm/s when its displacement is 1.5 cm and 55.0 cm/s when its displacement is 8.0 cm.

a. What is the oscillator’s maximum speed?

b. What is the oscillator’s maximum amplitude?

Homework Equations

A= sqroot(X^2+(V^2/w^2)
Vmax=wA

The Attempt at a Solution

I attempted to find the angular frequency but even with w=sqroot(k/m) i couldn't find a way to solve for w

 

[gneill]

Write expressions for the total energy for the two known points (sum of PE and KE). There will be a single unknown to solve for. After that you should be able to continue.

Conservation of energy is a powerful tool for these type of problems.

 

[jjd101]

i did this and solved for the Spring constant since this is what is not given and got K=147.4 ? correct ?

 

[gneill]

i did this and solved for the Spring constant since this is what is not given and got K=147.4 ? correct ?

Yup. You should be able to continue "as usual" from here.

 

[jjd101]

I did this and got max velocity as 121.7cm/s and max amplitude as 8.97cm. right?