Answer:
Explanation:
According to first law of thermodynamics:
∆U= q + w
= 10kj+(-70kJ)
-60kJ
, w = + 70 kJ
(work done on the system is positive)
q = -10kJ ( heat is given out, so negative)
∆U = -10 + (+70) = +60 kJ
Thus, the internal energy of the system decreases by 60 kJ.
As the metal expands as does the road bed so neither really effevts those foing over the bridge. as it is hot the metal will expand and so will most tarmac on roads.
Answer:
a spark
Explanation:
a spark would be the most smartest
The incident ray will have an angle of reflection of 30 degrees (made with a surface normal to the mirror surface). The reflected ray will make an angle of 60 degrees (90 - 30 degrees) with the mirror surface.
A light that is 3.98 times the distance from its source will have an intensity of 15.8404W/m^2
<h3>Calculation of light intensity</h3>
The relationship between the distance of light and intensity is that intensity varies inversely with the square of the distance from the source.
That is to say,if the distance of light is increased by 3.98 times, the light intensity is decreased by square of 3.98.
Therefore, the intensity is 3.98² = 15.8404W/m^2
Learn more about light intensity here:
brainly.com/question/2114560
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