Answer:
Efficiency
Explanation:
- The amount of mechanical work an engine can do per unit of heat energy it uses is called its efficiency.
- It is also defined as the output divided by the total electrical power consumed.
- In terms of heat, efficiency of engine is given by :

are output heat and input heat respectively.
Hence, the correct option is (d) "efficiency"
Answer:
At higher elevations, there are fewer air molecules above a given surface than a similar surface at lower levels. ... Since most of the atmosphere's molecules are held close to the earth's surface by the force of gravity, air pressure decreases rapidly at first, then more slowly at higher levels.
Explanation:
Astronomers find white dwarfs that distinguish them from main sequence stars because white dwarfs get really hot, we can search for their ultraviolet radiation.
<h3>What is a white dwarf?</h3>
A white dwarf is a very hot star that radiated much energy in the form of ultraviolet radiation.
This UV radiation is initially very bright and then these stars become red with time.
In conclusion, Astronomers find white dwarfs they can search for their ultraviolet radiation.
Learn more about white dwarfs here:
brainly.com/question/19602278
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You're talking about a grain of sand or a stone or a rock that's drifting in space, and then the Earth happens to get in the way, so the stone falls down to Earth, and it makes a bright streak of light while it's falling through the atmosphere and burning up from the friction.
-- While it's drifting in space, it's a <em>meteoroid</em>.
-- While it's falling through the atmosphere burning up and making a bright streak of light, it's a <em>meteor</em>.
-- If it doesn't completely burn up and there's some of it left to fall on the ground, then the leftover piece on the ground is a <em>meteorite</em>.
<h3><u>Answer;</u></h3>
Mechanical advantage
<h3><u>Explanation;</u></h3>
- Mechanical advantage is the ratio of force output from a machine divided by the force input into the machine.
- Mechanical advantage measures the machine's force-magnifying effect. It is an advantage gained by using simple machines to accomplish work with less effort.
- The formula is; M.A = output force/ Input force