Explanation:
The chemical properties of an element are determined by the configuration of its electrons in orbit around its nucleus. ... See a Periodic Table of the Elements. The number of protons in the nucleus of an atom is its Atomic Number.
The centripetal force exerted on the automobile while rounding the curve is 
<u>Explanation:</u>
given that
Objects moving around a circular track will experience centripetal force towards the center of the circular track.
Edwin Hubble calculated the expansion rate of the
universe. The evidence that he base his calculation is the differences in
redshift for galaxies. The answer is letter B. the red shift of galaxies was
directly proportional to the distance of the galaxy from earth. It means that bodies farther away from Earth
were moving away faster. The Hubble’s constant is the ratio of distance to
redshift equal to 170 kilometers per second per light year of distance.
Refer to the 2th Law of Newton
F = m. a
F = 15 x 2.8 = 42 N
