Answer:
a. Stars all warm objects
c. Some unstable atomic nuclei
Explanation:
Gamma rays are photons of very high energy (beyond 100keV) enough to remove an electron from its orbit.
They have a very short wavelength, less than 5 meters from the peak, and can be produced by nuclear decay, especially in the breasts of massive stars at the end of life.
They were discovered by the French chemist Paul Villard (1860 to 1934).
While X-rays are produced by electronic transitions in general caused by the collision of an electron with an atom at high speed, gamma rays are produced by nuclear transitions.
Gamma rays produce damage similar to those caused by X-rays or ultraviolet rays (burns, cancer and genetic mutations).
The sources of gamma rays that we observe in the universe come from <u>massive stars (hypernovas) or some warm objects on the space</u> that end their lives by a gravitational collapse that leads to the formation of a neutron star or a black hole, as well as <u>unstable radioactive nuclei </u>that emit radiation gamma to reach its steady state.
Answer:
the final speed of the rain is 541 m/s.
Explanation:
Given;
acceleration due to gravity, g = 9.81 m/s²
height of fall of the rain, h = 9,000 m
time of the rain fall, t = 1.5 minutes = 90 s
Determine the initial velocity of the rain, as follows;

The final speed of the rain is calculated as;

Therefore, the final speed of the rain is 541 m/s.
Answer:
D)
Explanation:
The Period-Luminosity relationship tells us that luminosity increases with the period, and of course the more luminosity a star has the more far away they can be seen, so from this we know that:
A) False since lower luminosities can be observed when they are close.
B) False since longer periods means higher luminosities
C) False since lower luminosities can be observed when they are close.
D) True: Variable stars with shorter periods have lower luminosities, so they can only be observed when they are close.