The average velocity of Sandy is given by the total distance covered S divided by the total time taken t:

The total distance covered is

while the total time taken is 2 hours + half an hour (for the rest) + 1 hour and half, so

Therefore, the average velocity is
Energy is the capacity to do some type of work
Base in your questions that ask what cause the bright lines seen in the emission spectrum and i think the best answer to that is the H2 gas is used when protons was heated so the electron absorb all the photons and get exited and resulted by given of a light.
1) The wavelength of the radiation emitted by the human skin is

the frequency of the radiation is related to the wavelength by

where

is the speed of light. Plugging numbers into the formula, we find the frequency of the radiation:

2) The frequency of this radiation is 313 GHz, and its wavelength

. If we look at the table of the electromagnetic spectrum
https://en.wikipedia.org/wiki/Electromagnetic_spectrum
We see that we are in the range of visible light (in particular, in the infrared range).
Therefore, the correct answer is <span>2. visible light .</span>
This is true; it needs to balance it’s charge. However, it could also be negative charges as well.