Answer:
1. Hot air is less dense and has moved upward allowing cool air to move downward which is less dens
(Convection current)
2. The ceiling has transferred heat to him by radiation.
Explanation:
During the day when air is heated as a result of the ceiling transferring heat to it, it becomes less dens and it gains energy, which make it lighter in weight than cooler air, this hot air moves upward allowing cooler air to move downward.
Complete question
The complete question is shown on the first uploaded image
Answer:
The velocity is 
Explanation:
From the question we are told that
a = nb
The length of the minor axis of the symbol of the Federation, a circle, seen by the observer at velocity v must be equal to the minor axis(b) of the Empire's symbol, (an ellipse)
Now this length seen by the observer can be mathematically represented as

Here t is the actual length of the major axis of of the Empire's symbol, (an ellipse)
So t = a = nb
and b is the length of the minor axis of the symbol of the Federation, (a circle) when seen by an observer at velocity v which from the question must be the length of the minor axis of the of the Empire's symbol, (an ellipse)
i.e h = b
So
![[\frac{1}{n} ]^2 = 1 - \frac{v^2}{c^2}](https://tex.z-dn.net/?f=%5B%5Cfrac%7B1%7D%7Bn%7D%20%5D%5E2%20%3D%20%201%20-%20%20%5Cfrac%7Bv%5E2%7D%7Bc%5E2%7D)
![v^2 =c^2 [1- \frac{1}{n^2} ]](https://tex.z-dn.net/?f=v%5E2%20%3Dc%5E2%20%5B1-%20%5Cfrac%7B1%7D%7Bn%5E2%7D%20%5D)
![v^2 =c^2 [\frac{n^2 -1}{n^2} ]](https://tex.z-dn.net/?f=v%5E2%20%3Dc%5E2%20%5B%5Cfrac%7Bn%5E2%20-1%7D%7Bn%5E2%7D%20%5D)

Sound travels fastest in solids. A sound is a vibration that travels in a longitudinal direction through a medium in the form of a mechanical wave.
<h3>What is sound?</h3>
A sound is a vibration that travels in a longitudinal direction through a medium in the form of a mechanical wave.
It can propagate through a solid, a liquid, or a gas as its medium. Solids go the fastest, liquids are slower, and gases are the slowest.
Sound travels the quickest through a solid because the molecules are packed together densely, allowing sound waves to leap from one molecule to the next more quickly.
Because the molecules in solids are packed the tightest, sound travels the quickest through them, whereas sound travels the slowest through gases.
To learn more about the sound refer to the link;
brainly.com/question/927975
Given that a hot air balloon lifts 50 meters vertically into the air and then comes back down.
The displacement is the distance covered in a specific direction.
When the balloon is going up, the displacement is positive. and when the balloon is coming down, the displacement is negative.
The total displacement = 50 - 50 = 0
The distance is a measurement of length between to different points or position.
For distance, there is no need to consider direction. There is no consideration for positive or negative signs
While the distance = 50 + 50 = 100 meters
Therefore, the correct answer is C
That is, The displacement is zero and the distance is 100 meters
Learn more on ; brainly.com/question/24662122
The angle of inclination is calculated using sin
function,
sin θ = 5 m / 20 m = 0.25
θ = 14.4775°
<span>The net force exerted is then calculated:
F net = m g sin θ = 20 * 9.8 * 0.25 </span>
F net = 49N
<span>Work is product of net force and distance:
W = F net * d = 49 * 20 </span>
<span>Work = 980 J </span>