Answer: The correct explanation is 2.
Explanation: The warm air is less dense (it expands) and thus it is lighter than the cold air so it will rise up to the floor. Therefore, when you place the heater on the floor it will warm the cold air which would then rise and be replaced by more cold air which would again get warm and rise and so on until the room is heated. This means that the correct explanation is 2.
On the other hand, if you put the heater at the ceiling, it will warm the cold air near the ceiling which would stay up there (it is lighter than the cold air under it). This means that the only way for the heat to spread from this ceiling level warm air to the lower levels is via conduction which is slow.
-30 I think sorry if I’m wrong
Answer: The answer is B. Add more solute (took test)
Explanation:
I., II., and IV. are examples of acceleration. III. isn't.
The image of the water tower and the houses is in the attachment.
Answer: (a) P = 245kPa;
(b) P = 173.5 kPa
Explanation: <u>Gauge</u> <u>pressure</u> is the pressure relative to the atmospheric pressure and it is only dependent of the height of the liquid in the container.
The pressure is calculated as: P = hρg
where
ρ is the density of the liquid, in this case, water, which is ρ = 1000kg/m³;
When it is full the reservoir contains 5.25×10⁵ kg. So, knowing the density, you know the volume:
ρ = 
V = ρ/m
V = 
V = 525 m³
To know the height of the spherical reservoir, its diameter is needed and to determine it, find the radius:
V = 
![r = \sqrt[3]{ \frac{3}{4\pi } .V}](https://tex.z-dn.net/?f=r%20%3D%20%5Csqrt%5B3%5D%7B%20%5Cfrac%7B3%7D%7B4%5Cpi%20%7D%20.V%7D)
r = ![\sqrt[3]{\frac{525.3}{4\pi } }](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B%5Cfrac%7B525.3%7D%7B4%5Cpi%20%7D%20%7D)
r = 5.005 m
diameter = 2*r = 10.01m
(a) Height for House A:
h = 15 + 10.01
h = 25.01
P = hρg
P = 25.01.10³.9.8
P = 245.10³ Pa or 245kPa
(b) h = 25 - 7.3
h = 17.71
P = hρg
P = 17.71.1000.9.8
P = 173.5.10³ Pa or 173.5 kPa