The incorrect statement about electromagnetic waves is C. induction of electric fields by changing magnetic fields only occurs if a conducting material is present.
Electromagnetic waves do not rely on any medium for propagation, which means that the generation of fields is irrespective of the presence of a conducting material.
Inertia- a tendency to do nothing or to remain unchanged
780 seconds, or 13 minutes.
In the future, please use proper capitalization. There's a significant difference in the meaning between mV and MV. One of them indicated millivolts while the other indicates megavolts. For this problem, I'll make the following assumptions about the values presented. They are:
Total energy = 1.4x10^11 Joules (J)
Current per flash = 30 Columbs (C)
Potential difference = 30 Mega Volts (MV)
First, let's determine the power discharged by each bolt. That would be the current multiplied by the voltage, so
30 C * 30x10^6 V = 9x10^8 CV = 9x10^8 J
Now that we know how many joules are dissipated per flash, let's determine how flashes are needed.
1.4x10^11 / 9x10^8 = 1.56E+02 = 156
Since each flash takes 5 seconds, that means that it will take about 5 * 156 = 780 seconds which is about 780/60 = 13 minutes.
