Let's see: frequency of cellular phone waves (GSM phones) is (800-1900 MHz). If we look at the table of the electromagnetic spectrum, we can see that this range is contained within the frequencies of the microwaves, which include waves in the range 300 MHz-300 GHz.
So, summarizing, the correct answer is "microwaves".
Answer:
The bell has a potential energy of 8550 [J]
Explanation:
Since the belt is 45 [m] above ground level, only potential energy is available. And this energy can be calculated by means of the following equation.
![E_{p}= W*h\\E_{p} = 190*45\\E_{p}=8550[J]](https://tex.z-dn.net/?f=E_%7Bp%7D%3D%20W%2Ah%5C%5CE_%7Bp%7D%20%3D%20190%2A45%5C%5CE_%7Bp%7D%3D8550%5BJ%5D)
Kepler derived his three laws of planetary motion entirely from
observations of the planets and their motions in the sky.
Newton published his law of universal gravitation almost a hundred
years later. Using some calculus and some analytic geometry, which
any serious sophomore in an engineering college should be able to do,
it can be shown that IF Newton's law of gravitation is correct, then it MUST
lead to Kepler's laws. Gravity, as Newton described it, must make the planets
in their orbits behave exactly as they do.
This demonstration is a tremendous boost for the work of both Kepler
and Newton.
