Answer:
91.87 m/s
Explanation:
<u>Given:</u>
- x = initial distance of the electron from the proton = 6 cm = 0.06 m
- y = initial distance of the electron from the proton = 3 cm = 0.03 m
- u = initial velocity of the electron = 0 m/s
<u>Assume:</u>
- m = mass of an electron =

- v = final velocity of the electron
- e = magnitude of charge on an electron =

- p = magnitude of charge on a proton =

We know that only only electric field due to proton causes to move from a distance of 6 cm from proton to 3 cm distance from it. This means the electric force force does work on the electron to move it from one initial position to the final position which is equal to the change in potential energy of the electron due to proton.
Now, according to the work-energy theorem, the total work done by the electric force on the electron due to proton is equal to the kinetic energy change in it.


Hence, when the electron is at a distance of c cm from the proton, it moves with a velocity of 91.87 m/s.
Answer:
The shanghai maglev train is capable of reaching speeds of up to 217.48 in mph
217.48 mph
Explanation:
Potential energy decreases and kinetic energy increases.
Potential energy is related to the height, since the wagon is going downhill, height decreases and potential energy decreases.
Kinetic energy is related to the speed, since the wagon is speeding up, kinetic energy increases.
Velocity (unit:m/s) of the wave is given with the formula:
v=f∧,
where f is the frequency which tells us how many waves are passing a point per second (unit: Hz) and ∧ is the wavelength, which tells us the length of those waves in metres (unit:m)
f=1/T , where T is the period of the wave.
In our case: f=1/3
∧=v/f=24m/s/1/3=24*3=72m