Answer:
The mass of the second sphere is 6.24 kg.
Step-by-step explanation:
Let the mass of second sphere be 'm₂' kg.
Given:
Mass of first sphere (m₁) = 3.12 kg
Initial speed of first sphere = 'u₁' (Assume)
Initial speed of second sphere (u₂) = 0 m/s
Final speed of system is one-third of 'u₁'. Let 'v' be the final speed.
So,
![v=(u_1)/(3)](https://img.qammunity.org/2021/formulas/physics/college/kae3w57kdtzun2yojl59l0dzdg82h7v1wy.png)
Now, the conservation of momentum holds true for the collision system.
Initial momentum is given as:
![P_i=m_1u_1+m_2u_2=m_1u_1+0=m_1u_1](https://img.qammunity.org/2021/formulas/physics/college/34ujweb47qxvw2we6pyxe35pqqo9vw3e8s.png)
Final momentum is given as:
![P_f=(m_1+m_2)v=(u_1)/(3)(m_1+m_2)](https://img.qammunity.org/2021/formulas/physics/college/5jafadik4om0vbkx631yqr1gwlzcfq27ua.png)
Now, from conservation of momentum, we have:
![P_i=P_f\\\\m_1u_1=(u_1)/(3)(m_1+m_2)\\\\3m_1=m_1+m_2\\\\m_2=3m_1-m_1=2m_1](https://img.qammunity.org/2021/formulas/physics/college/749mv6wh7wa37a3gu0e443lnuzxwei8nls.png)
Plug in 3.12 kg for m₁ and solve for
. This gives,
![m_2=2* 3.12\ kg = 6.24\ kg](https://img.qammunity.org/2021/formulas/physics/college/zgjxhfxthg95t278yi1yvsu63ippx4750j.png)
Therefore, the mass of the second sphere is 6.24 kg.