Question

A ball of mass 5 kg hangs from a spring and oscillates with a time period of 2 sec. If the ball is removed, the spring shortens by

Answer 1

Here,
Time taken = 2 pi × m × k
= 2 pi 5 × k
k = 5 N/m
Now,
Let length be x, so
Kx = mg
Therefore,
M × g = 5 × 2 = 10 N

Answer 2

For a spring-mass system the time period of the system is

T=2πmk−−√⇒2π=2π5k−−√⇒k=5 N/m

Let the length of the spring decreases by x m.

Then

kx=mg⇒5x=5×10⇒x=10 m