physics simple harmonic motion question

Test Preparation AP Sciences
1

<p>a body of mass m is suspended from a rubber cord with stiffness constant k. the maximum distance over which the body can be pulled down further for the body's oscillation to remain harmonic is
a) mg/k
b) 2mg/k
c) 2k/mg
d) mg/2k</p>

<p>the ans is a)</p>

<p>thanks :)</p>

2

<p>the extension should not be more than the normal extension produced when the mass is freely hanging with the rope under gravity.</p>

<hr>

<p>=> mg=kx
=> x=mg/k</p>

<p>not sure though</p>

3

<p>thanks a ton!</p>