That they sometimes explode?
Answer:
Because it kills people. I have had 6 relatives who have died from it in the past 2 years. It's horrible.
Explanation:
If you're wondering what causes cancer, it is rapid and uncontrollable cell regeneration. The majority of cancers result from random mutations arising during DNA replication in the normal stem cells required during development and tissue maintenance.
The force between two system is inversely proportional to the square the distance between them. The indirect proportion between these items may be expressed as,
F = k / d²
where k is the constant proportionality. Substituting the known values,
0.68 N = k / (1 m)² ; k = 0.68
For the second case,
F = 0.68 / (0.5 m)² = 2.72 N
Thus, the answer is 2.72 N.
Wavelength = speed / frequency.
Wavelength = 3x10^8 m/s / 30 hz
Wavelength = 10 million meters
1/2 wavelength = 5 million meters
(that's about 3,100 miles)
I'm pretty sure the frequency is wrong in the question.
I think it's actually 30 kHz, not 30 Hz.
That makes the antenna about 3.1 miles long.