Question

a ball of mass 1g and charge 10^-8 moves from a point A where V=600volt to the point B where potential is zero. Velocity of the ball at B is 20cm/s .The velocity of ball at the point A will be​

Answer 1

As we have learnt,

 

Work energy relation -

W= U_{f}-U_{i}

 

 

- wherein

U_{f}- \, final\, P.E

U_{i}-\, initial\, P.E.

 

By using,

\frac{1}{2}m(v_1^{2}- v_2^{2}) \Rightarrow \frac{1}{2}\times 10^{-3}(v_{1}^{2} - (0.2)^{2}) = 10^{-8}(600 - 0)\Rightarrow v_1 = 22.8cm/s