Answer:
![mg +(mv^(2))/(r)](https://img.qammunity.org/2020/formulas/physics/college/lo20zclp999a3xo145hyq4ho9gr1fw85jj.png)
Step-by-step explanation:
At the bottom of the pipe :
= Normal force acting in upward direction
= mass of the ball
= weight of the ball acting in downward direction = mg
= speed of the ball at the bottom
= radius of curvature
Force equation for the motion of ball is given as
![N - W = (mv^(2))/(r)](https://img.qammunity.org/2020/formulas/physics/college/cjoapsxebckax5n6wae1wxsk0glyhb18ro.png)
![N - mg = (mv^(2))/(r)](https://img.qammunity.org/2020/formulas/physics/college/jmvacp0qpqrogxqtvptmtxsb0ms05p9154.png)
![N = mg +(mv^(2))/(r)](https://img.qammunity.org/2020/formulas/physics/college/1pfmwduz1gws9hmxpzxc0urmbpy001hzw0.png)