# Mass added to a spring to increase period of oscillation

## Homework Statement

7. Mass m is oscillating on the end of a spring. How much mass must be added in order for the
period of oscillation to increase by a factor of two?
A.m
B.2m
C.3m
D.4m
E.8m

## Homework Equations

f=-kx
w= $$\sqrt{k/m}$$
T = 2$$\pi$$$$\sqrt{m/k}$$

## The Attempt at a Solution

since period (T) is proportional to the square root of m and we want 2t, i had 2T=$$\sqrt{m}$$ so 2^2 =4

the given answer is 3 and i dont know how this was chosen