800,000 km/hr is the answr
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
It would help if you listed the needed vocabulary words.
Answer:
Explanation: The part of the wave he is traveling on is the crest
So check it out you can just use the old formula

instead of deviding distance and time multiply velocity and time
so the formula would be
