Elastic potential energy is given by formula

here we know that


Now using above formula we have


So elastic potential energy in the chord is 14400 J
Incomplete question as we have not told to find what quantity.The complete question is here
A spherical capacitor contains a charge of 3.50 nC when connected to a potential difference of 210.0 V. Its plates are separated by vacuum and the inner radius of the outer shell is 5.00 cm.calculate: (a) the capacitance; (b) the radius of the inner sphere; (c) the electric field just outside the surface of the inner sphere.
Answer:
(a) 
(b) 
(c)
Explanation:
Given data

For part (a)
The Capacitance given by:

For part (b)
The Capacitance of coordinates is given as

For part (c)
The electric field according to Gauss Law is given by:

Answer:
¨Facts you didn´t know¨ or ¨unknown facts¨
Explanation: