Answer:
A. The closest point in the Moon's orbit to Earth
Explanation:
The perigee is defined as the closest point in the orbit of an object (such as a satellite) from the centre of the Earth. In this case, the Earth's satellite is the Moon, so the perigee is defined as the closest point in the Moon's orbit to Earth. so option A is the correct one.
Let's see instead the names of the other options:
B. The farthest point in the Moon's orbit to Earth --> this point is called apogee
C. The closest point in Earth's orbit of the Sun --> this point is called perihelion
D. The Sun's orbit that is closest to the Moon --> this point has no specific name
Answer:
c) Very dangerous and users must not override devices designed to protect from exposures.
Explanation:
X-ray is a form of high energy electromagnetic radiation and are part of the electromagnetic spectrum.
X-ray radiation from diffraction and fluorescence instruments is very dangerous because of their high energy and wavelength.
Hence, users must not override devices designed to protect from exposures. The best shielding device to protect one from exposure is Lead.
The energy of a photon is given by
where
is the Planck constant
f is the frequency of the photon
In our problem, the frequency of the light is
therefore we can use the previous equation to calculate the energy of each photon of the green light emitted by the lamp:
If the sunlight is covered up by clouds or other things the temperature will be a little cooler, because the sun rays arent hitting things and making them warmer<span />
