Answer:
D. Opening the front door in winter to filter and clean warm ai
Explanation:
All of the following are examples of ways to improve energy efficiency of heating systems, except _______.
A. Closing off rooms that aren’t in use.
B. Frequently cleaning the furnace filter.
C. Fixing cracks in the walls and floor.
D. Opening the front door in winter to filter and clean warm air
for an heating systems it is better to keep the front door shut so that all the heat energy does not escape outside.
when heat energy is within a closed system ,it can still be utilized to keep the inhabitants warm otherwise there will be an exchange with the cold from winter fall outside the air, and the heating system's efficiency will be reduced
The air pressure inside the balloon is: 0.1432 Pa
The formulas and procedures that we will use to solve this problem are:
Where:
- a = area of the sphere
- r = radius
- π = mathematical constant
- P = Pressure
- F = Force
- a = surface area
Information about the problem:
- r = 5.0 m
- F = 45 N
- 1 Pa = N/m²
- 1 N = kg * m/s²
- a=?
- P=?
Using the formula of the sphere area we get:
a = 4 * π * r²
a = 4 * 3.1416 * (5.0 m)²
a = 314.16 m²
Applying the pressure formula we get:
P = F/a
P = 45 N/314.16 m²
P = 0.1432 Pa
<h3>What is pressure?</h3>
It is a physical quantity that expresses the force applied on the area of a surface.
Learn more about pressure at: brainly.com/question/26269477
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Answer:

Explanation:
Given:
- mass of steam,

- temperature of steam,

- temperature of resultant water,

We have,
- latent heat of vapourization of water,

- specific heat capacity of water,

<em>When we cool the steam of 100°C then firstly it loses its latent heat to convert into water of 100°C and the further cools the water.</em>
<u>Now the heat removed from steam to achieve the final state of water:</u>




Power = 1800W (or 1.8KW by dividing by 1000)
Time = 3 hours
Power = energy/ time
1.8KW = energy/ 3
x3
5.4Kw/h= energy
(5.4KJ or 5400J used)
$0.15 Kw/h
$0.15 X 5.4 = 0.81
Thus, cost $0.81
Hope this helps!