Explanation is in the file
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A set of two forces that are in opposite directions, have equal magnitudes and act on different objects
Use the following formula for the electric field strength between two parallel plates:
E = V/d
where,
V: potential difference = 25V
d: distance between plates = 5 cm = 0.05 m
Replace the previous values of the parameters into the formula for E:

Hence, the electric field strength is 500V/m
Normal force = 200(9.81) = 1962 N
Friction force = 1962 * .4 = 784.8
power = force * distance / time = 784.8 * 5 = 3924 Watts
Watts = Joules / sec
3924 x 180 = 706,320 Joules