Who's your favorite singer and WHT your favorite song
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Answer:
<em>Heat rejected to cold body = 3.81 kJ</em>
Explanation:
Temperature of hot thermal reservoir Th = 1600 K
Temperature of cold thermal reservoir Tc = 400 K
<em>efficiency of the Carnot's engine = 1 - </em><em> </em>
eff. of the Carnot's engine = 1 -
eff = 1 - 0.25 = 0.75
<em>efficiency of the heat engine = 70% of 0.75 = 0.525</em>
work done by heat engine = 2 kJ
<em>eff. of heat engine is gotten as = W/Q</em>
where W = work done by heat engine
Q = heat rejected by heat engine to lower temperature reservoir
from the equation, we can derive that
heat rejected Q = W/eff = 2/0.525 = <em>3.81 kJ</em>
Answer:
And we can find this probability with this difference:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.
So then the percentage usable are 94,6%
Explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the diameters of a population, and for this case we know the distribution for X is given by:
Where and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability with this difference:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.
So then the percentage usable are 94,6%