Answer:
The final speed of the railroad car
V= 1.14 
Explanation:
That's the final speed of the both railroad car
The Doppler effect is the term that best describes the change in frequency of waves when there is motion between the source of the waves and the observer. The correct option among all the options that are given in the question is the first option or option "a". I hope the answer helps you.
-The group 7 elements are also known as the halogens.
They include fluorine, chlorine, bromine and iodine, which all have seven
electrons in their outer shell.
-The noble gases
make a group of chemical elements with comparable properties; under standard
conditions, they are all odorless, colorless, monatomic gases with very low
chemical reactivity. The six noble gases that occur naturally are helium, neon,
argon, krypton, xenon, and the radioactive radon. FACT: They can also act like
a glow stick.<span>[ID1] </span>
<span> [ID1]</span>
<span>they took advantage of innovations in sailing technolgy that allowed ships such as the caravel to sail against the wind.</span>
Similar elements with similar properties were in the same groups and periods for instance lithium(Li) and sodium(Na) are alkaline metals and so belong to the same group (that is group 1).Also Hydrogen(H) and Helium(He) both have only one shell or energy level and so belong to the same period.
