<span>A substance that cannot be divided into smaller substances by chemical means is called an Element. (gold, iorn,ect...)
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Explanation:
Let h is the height of the plane above ground. x is the horizontal distance between the ground and the airport. Let s(t) is the distance between the plane and the airport. So,
...........(1)
Given, h = 4, x = 40 and s(t) = -20 mph
Differentiate equation (1) wrt t
When x = 40, 
So, the speed of the airplane is 241.14 m/s. Hence, this is the required solution.
Answer: What is the difference of physical quanity and a unit?
Explanation: If you are working science or math problems, the answer to this question is that quantity is the amount or numerical value, while the unit is the measurement. For example, if a sample contains 453 grams, the quantity is 453 while the unit is grams.
Answer:
The answer is 30 degrees.
Explanation:
The angle between the index and pinky fingers is 15 degrees.
Twice this angle is 2×15=30degrees.
Answer:
<em>In the case of a solar thermal panel we are trying to heat above the ambient temperature so conduction and convection will work against us by taking heat from the panel to the out- side world. ... The sun (at 6000 C surface temperature) is hotter than the solar panel so the panel will get hot due to the solar radiation.</em>
Explanation:
