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zmey [24]
2 years ago
15

Which letter explains why no machine is 100 percent efficient.

Physics
1 answer:
kondaur [170]2 years ago
4 0

Answer:

A

Explanation:

Think about rubbing your hands together- the friciton produces heat

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Measuring the amount of deuterium in the universe allows us to set a limit on _________.
Mademuasel [1]

Answer:

the density of ordinary (baryonic) matter in the universe

Explanation:

 Deuterium detection is of interest because the amount of it may be related to the amount of dark matter in the universe, but precise measurements have been difficult to obtain. Due to the way in which deuterium was created in the Big Bang, an exact measurement of the amount of deuterium would allow scientists to set limits on the models of the great explosion.

Also, an exact measure of deuterium would be an indicator of the cosmic density of barions (ordinary matter), and that density of barions would indicate whether ordinary matter is dark and is found in regions such as black holes, gas clouds or brown dwarfs, or it is bright and can be found in the stars. This information will help scientists who try to understand the very beginning of our universe.

4 0
3 years ago
What is the wavelength of visible light emitted at 4.2 x 10^8 Answer in units of M
Ber [7]

Answer:

0.714 m

Explanation:

From the question,

v = λf......................... Equation 1

Where v = velocity of visible light, f = frequency of visible light, λ = wave length of visible light.

make λ the subject of the equation

λ = v/f.................. Equation 2

Given: f = 4.2×10⁸ Hz

Note: Light is an electromagnetic wave, and all electromagnetic waves travels with the same speed (3×10⁸ m/s)

Constant: v = 3×10⁸ m/s

Substitute these values into equation 2

λ = 3×10⁸/4.2×10⁸

λ = 0.714 m

8 0
3 years ago
Stars are called blackbody radiators because they
scoundrel [369]
The answer is D) absorb most of the light that falls on them

A blackbody is an object that absorbs most (theoretically all) of the light that falls on it. Stars are called black bodies because they demonstrate something close to this property. Why do they appear white and not black? As black body radiators heat up, they slowly turn from black to grey to white, according to the human eye. Since stars are incredibly hot, they appear white to us. 
8 0
3 years ago
How much power is used if a force of 54 newtons is used to pull a wagon a distance of 10 meters in 6 seconds?
AnnZ [28]
First, calculate the work done: 54 x 10 = 540J.
Now calculate power: 540 / 6 = 90.
The answer is 90W.

Hope this helps.
7 0
3 years ago
Read 2 more answers
What is the difference between a 4x100 and a 4x400 relay
qaws [65]
A 4x100 relay is where 4 people run 100 meters and a 4x400 relay is where 4 people run 400 meters
6 0
3 years ago
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