# Simple Harmonic Motion Question.

Student3.41

## Homework Statement

When a mass is hung from a spring, the spring elongates by 10.6cm. What will the period of the resulting oscillations be if the mass is displaced from equilibrium?

## Homework Equations

T=2(pi)$$\sqrt{m/k}$$

## The Attempt at a Solution

I have no clue what do with this question, if I am not given a mass or spring constant. I tried using Newtons 2nd Law to find k but without knowing the mass I ended up with two unknowns.

cupid.callin
well do you know how to find force due to a spring?

Student3.41
well do you know how to find force due to a spring?

Are you talking about hooke's law? F=-kx

cupid.callin
yes!!!

Now, which force do you think is responsible for the decrease in height of mass (not -kx one)!!!

Student3.41
yes!!!

Now, which force do you think is responsible for the decrease in height of mass (not -kx one)!!!

Well the only other force acting on the object is gravity..

cupid.callin
yes ... now as you will know that at point where net acc. on body will be zero ... Fnet = 0

can you figure out m/k now?

Student3.41
yes ... now as you will know that at point where net acc. on body will be zero ... Fnet = 0

can you figure out m/k now?

Fnet=0
Fs-mg=0
kx=mg
x/g=m/k

(0.106/9.81)=m/k

=0.104= m/k

T=2(pi)square(0.104)root