Galaxies are sprawling systems of dust, gas, dark matter, and anywhere from a million to a trillion stars that are held together by gravity. Nearly all large galaxies are thought to also contain supermassive black holes at their centers.
Answer;
D. rocket engines are not dependent on oxygen from the air.
Explanation;
-Jet engines and rockets work on the same principle. They produce thrust through an internal pressure difference and, as explained by Newton’s Third Law of Motion, eject exhaust gases in an equal and opposite direction.
-The main difference between them is that jets get the oxygen to burn fuel from the air and rockets carry their own oxygen, which allows them to operate in space.
Additionally, Jet engines have two openings (an intake and an exhaust nozzle). Rocket engines only have one opening (an exhaust nozzle).
<span>Formula-
E = hc/ {wavelength}
Given in quation-wavelength=12.4 cm
We know the value of h and c.
h=6.626 * 10^-34 Js
c= 2.997 * 10^8 m/s
wavelength=12.4 cm converted to 0.124 m
E = [ 6.626 * 10^-34 Js * 2.997 * 10^8 m/s ] / 0.124 m
E = 1.60 * 10^-24 J
1.60 * 10^-24 J of energy of exactly one photon of this microwave radiation have.</span>
W= FxD. Since the weight is not put into force you’re going to convert it by multiplying it by 9.8 (gravity). 76kg x 9.8 = 7448. Then multiply that by the distance (2.5). Your answer is 1862.