Air and water have a good day
Complex reaction time involves selecting a specific and correct response from several choices when presented with several different stimuli.
Answer: A
Answer:
a) m=20000Kg
b) v=0.214m/s
Explanation:
We will separate the problem in 3 parts, part A when there were no coals on the car, part B when there is 1 coal on the car and part C when there are 2 coals on the car. Inertia is the mass in this case.
For each part, and since the coals are thrown vertically, the horizontal linear momentum p=mv must be conserved, that is,
, were each velocity refers to the one of the car (with the eventual coals on it) for each part, and each mass the mass of the car (with the eventual coals on it) also for each part. We will write the mass of the hopper car as
, and the mass of the first and second coals as
and
respectively
We start with the transition between parts A and B, so we have:

Which means

And since we want the mass of the first coal thrown (
) we do:



Substituting values we obtain

For the transition between parts B and C, we can write:

Which means

Since we want the new final speed of the car (
) we do:

Substituting values we obtain

Answer:
1. A glass of water at 80°C because the more heat it will recieve, the more temperature increases. Heat is a sort of energy so the more it is heated, the more energy the water will recieve. So in comparison to 20°C, 80°C has more energy in it because it has a higher temperature.
2. An aluminium can at 30°C because the more heat it will recieve, the more temperature increases. Heat is a sort of energy so the more it is heated, the more energy the aluminium will recieve. So in comparison to 20°C, 30°C has more energy in it because it has a higher temperature.
Brainliest pweaseee if it is the correct answer! <3 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~