Answer:
![v = √(2gy)](https://img.qammunity.org/2020/formulas/physics/high-school/zbk4bmpk636l0m1ko20ispwr8ovac2kamv.png)
Step-by-step explanation:
Formula for Kinetic Energy
![E_k = (mv^2)/(2)](https://img.qammunity.org/2020/formulas/physics/college/mh5gkvg51ripni04e5hbvkwlpe5np0w6sn.png)
Formula for Potential Energy
where g = 9.81 m/s
When the ball travels a distance y downward, its potential energy would be converted to kinetic energy. Hence, the ball loses altitude and gains speed
By law of total energy conservation
![E_k = E_p](https://img.qammunity.org/2020/formulas/physics/high-school/xwtk3k0ou38uujk8y48vbsk768rlzu8tk5.png)
![(mv^2)/(2) = mgy](https://img.qammunity.org/2020/formulas/physics/high-school/kxdih19aibl4anquidkyphszjf7ydod62f.png)
![v^2 = 2gy](https://img.qammunity.org/2020/formulas/physics/high-school/4zcoremlrp8ykw4dh4iz08t060h2uycwa0.png)
![v = √(2gy)](https://img.qammunity.org/2020/formulas/physics/high-school/zbk4bmpk636l0m1ko20ispwr8ovac2kamv.png)