<u>O</u><u>p</u><u>t</u><u>i</u><u>o</u><u>n</u><u> </u><u>C</u><u> </u><u>i</u><u>s</u><u> </u><u>t</u><u>h</u><u>e</u><u> </u><u>a</u><u>n</u><u>s</u><u>w</u><u>e</u><u>r</u>
<h3 /><h3><em>S</em><em>m</em><em>a</em><em>l</em><em>l</em><em> </em><em>Explanation</em><em>:</em><em>-</em></h3>
The reactants are charcoal that is unlit + oxygen and the products are the burnt charcoal + energy.
(Explanation with formula and reason attached. Check it.)

1. its must be B and 2. must be C
Answer:
X-rays go all the way through the body, but ultraviolet rays do not.
Explanation:
An x-ray will show inside the body, but uv light isn't strong enough to go all the way through the body.
Answer:
For the first situation, we first need to find the mass of the second train car.
In order to do that, we apply the conservation of the amount of movement:

and we have as a result:
m2 = 289.6875
For the second situation, also we will apply the conservation of the amount of movement:

and we have as a result:
V = 2.64 (it is moving to the right)