Answer:
The potential difference between the plates is 596.2 volts.
Explanation:
Given that,
Capacitance 
Charge 
Separation of plates = 0.313 mm
We need to calculate the potential difference between the plates
Using formula of potential difference

Where, Q = charge
C = capacitance
Put the value into the formula


Hence,The potential difference between the plates is 596.2 volts.
The sphere slow down due to friction force between the surface of the sphere and the surface on that the sphere is rolling . The friction force acting against the motion of the sphere. Thats why it is slowed down. In fact not only a sphere, anything can not slow down untill a force act against it's motion.
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