The bullet train the shinkansen, the japanese "bullet" train, runs at high speed from tokyo to nagoya. riding on the shinkansen, you notice that the frequency of a crossing signal changes markedly as you pass the crossing. as you approach the crossing, the frequency you hear is f; as you recede from the crossing the frequency you hear is 2f/3.what is the speed of the train?

68.6 m/s

Explanation:

v = Speed of sound in air = 343 m/s

u = Speed of train

= Actual frequency

From the Doppler effect we have the observed frequency as

When the train is approaching

When the train is receeding

Dividing the above equations we have

The speed of the train is 68.6 m/s

probably not if net force is zero

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it