Answer:
Mass attached to the spring is 41.95 kg
Step-by-step explanation:
We have given time period of the spring T = 2.1 sec
Let the mass attached is m
And spring constant is k
We know that time period is given by
![T=2\pi \sqrt{(m)/(k)}](https://img.qammunity.org/2020/formulas/physics/high-school/jvsrxrn49rqnjrrg60zil88jyoq4faceox.png)
---------eqn 1
Now if the mass is increased by 68.10 kg then time period become 3.4 sec
So
------eqn 2
Now dividing eqn 1 by eqn 2
![(2.1)/(3.4)=\sqrt{(m)/(m+68.10)}](https://img.qammunity.org/2020/formulas/physics/high-school/1x4l5ussfqy8nfo205whnnhae8ly3301f1.png)
![0.381=(m)/(m+68.10)](https://img.qammunity.org/2020/formulas/physics/high-school/h8af1nnijmsoh1hcb3oposz1euxk3ayl9d.png)
![m=41.95 kg](https://img.qammunity.org/2020/formulas/physics/high-school/kdvx3cuajmv1kcndh70l44ok0s65xnu8e7.png)
So mass attached to the spring is 41.95 kg