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3 years ago

A typical home in the northern U.S. might require 120 MBtu of heat for the average winter.

Physics

1 answer:

eimsori [14]3 years ago

0 0

200 MBtu of heat

Explanation:

As provided in the question, heat supplying natural gas furnace operates at 60% efficiency. It means that out of 100 units of heat energy produced by the furnace, only 60 units of heat can be transferred.

Thereby as the demand of the heat energy is 120 MBtu, amount of gas that needs to be purchased equals-

∴ 60% of (cubic metres of gas that needs to be purchased) = 120 MBtu

⇒ (60/100) * gas = 120

⇒ Gas= 120*100/60

∴ Cubic metres of gas that needs to be purchased= 200MBtu

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Soap bubbles can display impressive colors, which are the result of the enhanced reflection of light of particular wavelengths f

Bogdan [553]

Answer:

the minimum wall thickness that will enhance the reflection of light is 146.9 nm

Explanation:

Given the data in the question;

At the first interface, a phase shift occurs as the incident light is in air that has less refractive index compare to the thin film of soap bubble.

At the second interface, no shift occurs,

condition for constructive interference;

t = ( m + 1/2) × λ/2n

where m = 0, 1, 2, 3 . . . . . .

now, the condition for the constructive interference;

t = mλ/2n

where t is the thickness of the soap bubble, λ is the wavelength of light and n is the refractive index of soap bubble.

so the minimum thickness of the film which will enhance reflection of light will be;

t $_{min$ = ( m + 1/2) × λ/2n

we substitute

t $_{min$ = ( 0 + 1/2) × 711 /2(1.21)

t $_{min$ = 0.5 × 711/2.42

t $_{min$ = 0.5 × 293.80165

t $_{min$ = 146.9 nm

Therefore, the minimum wall thickness that will enhance the reflection of light is 146.9 nm

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3 years ago

A rigid object has a mass of 18kg and a radius of gyration of 0.3m. It is initially rotating clockwise about a fixed axis at its

ElenaW [278]

Answer:

:0 i dont know

Explanation:

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2 years ago

Maximum current problem. If the current on your power supply exceeds 500 mA it can damage the supply. Suppose the supply is set

VikaD [51]

To solve this problem we will apply Ohm's law. The law establishes that the potential difference V that we apply between the ends of a given conductor is proportional to the intensity of the current I flowing through the said conductor. Ohm completed the law by introducing the notion of electrical resistance R. Mathematically it can be described as

$V = IR \rightarrow R = \frac{V}{I}$

Our values are

$I = 500mA = 0.5A$

$V = 37V$

Replacing,

$R = \frac{V}{I}$

$R = \frac{37}{0.5}$

$R = 74 \Omega$

Therefore the smallest resistance you can measure is $74 \Omega$

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3 years ago

What is the most effective means of establishing awareness of hazards in commercial, industrial, and storage facilities with lar

coldgirl [10]

Answer:

C: Contacting the facilities.

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3 years ago

Alex is standing still and throws a football with a speed of 10 m/s to his friend, who is also standing still. The two friends a

Phantasy [73]

The question is incomplete. It comes with a set of answer choices.

These are the answer choices:

Alex observes it as 10 m/s, and his friend observes it as less than 10 m/s.

Alex observes it as less than 10 m/s, and his friend observes it as 10 m/s.

Both Alex and his friend observe it as 10 m/s.

Both Alex and his friend observe it as less than 10 m/s.

Answer: Both Alex and his friend observe it as 10 m/s.

Justification:

1) The speed is relative to the frame of reference.

2) It is said that the both Alex and his friend are standing still.

3) Then, the speed they both see is the same, 10 m/s, respect the Earth (where they are standing still).

Of course, Alex is watching the ball moving away and his friend is seing it approaching, but it is not relevant for the question, as it deals with the speed which is only about magnitude, not direction.

7 0

3 years ago

Read 2 more answers