Answer:
Given:
high temperature reservoir ![T_{H} =1000k](https://tex.z-dn.net/?f=T_%7BH%7D%20%3D1000k)
low temperature reservoir ![T_{L} =400k](https://tex.z-dn.net/?f=T_%7BL%7D%20%3D400k)
thermal efficiency ![n_{1}= n_{2}](https://tex.z-dn.net/?f=n_%7B1%7D%3D%20n_%7B2%7D)
The engines are said to operate on Carnot cycle which is totally reversible.
To find the intermediate temperature between the two engines, The thermal efficiency of the first heat engine can be defined as
![n_{1} =1-\frac{T}{T_{H} }](https://tex.z-dn.net/?f=n_%7B1%7D%20%3D1-%5Cfrac%7BT%7D%7BT_%7BH%7D%20%7D)
The thermal efficiency of second heat engine can be written as
![n_{2} =1-\frac{T_{L} }{T}](https://tex.z-dn.net/?f=n_%7B2%7D%20%3D1-%5Cfrac%7BT_%7BL%7D%20%7D%7BT%7D)
The temperature of intermediate reservoir can be defined as
![1-\frac{T}{T_{H} } =1-\frac{T_{L} }{T} \\T^2=T_{L} T_{H} \\T=\sqrt{T_{L} T_{H} }\\T=\sqrt{400*1000} =632k](https://tex.z-dn.net/?f=1-%5Cfrac%7BT%7D%7BT_%7BH%7D%20%7D%20%3D1-%5Cfrac%7BT_%7BL%7D%20%7D%7BT%7D%20%5C%5CT%5E2%3DT_%7BL%7D%20T_%7BH%7D%20%5C%5CT%3D%5Csqrt%7BT_%7BL%7D%20T_%7BH%7D%20%7D%5C%5CT%3D%5Csqrt%7B400%2A1000%7D%20%3D632k)
Answer:
D
Explanation:
To know which is most or least cost-effective, it's not enough to look at only the per day rate, or only the time to complete. You have to multiply them to get the total cost of the project.
![\left[\begin{array}{ccccc}&Cost\ per\ day\ (\$)&Time\ to\ complete\ (days)&Total\ cost\ (\$)\\Zoe&500&8&4000\\Greg&650&10&6500\\Orion&400&12&4800\\Jin&700&5&3500\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccccc%7D%26Cost%5C%20per%5C%20day%5C%20%28%5C%24%29%26Time%5C%20to%5C%20complete%5C%20%28days%29%26Total%5C%20cost%5C%20%28%5C%24%29%5C%5CZoe%26500%268%264000%5C%5CGreg%26650%2610%266500%5C%5COrion%26400%2612%264800%5C%5CJin%26700%265%263500%5Cend%7Barray%7D%5Cright%5D)
As you can see, Greg is the least cost-effective because he charges the most for the project.
Answer:
i dont know but i will take the points tho hahah
Explanation:
Answer:
(a). the resultant force in the direction of the freestream velocity is termed the drag and the resultant force normal to the freestream velocity is termed the lift
Explanation:
When a fluid flows around the surface of an object, it exerts a force on it. This force has two components, namely lift and drag.
The component of this force that is perpendicular (normal) to the freestream velocity is known as lift, while the component of this force that is parallel or in the direction of the fluid freestream flow is known as drag.
Lift is as a result of pressure differences, while drag results from forces due to pressure distributions over the object surface, and forces due to skin friction or viscous force.
Thus, drag results from the combination of pressure and viscous forces while lift results only from the<em> pressure differences</em> (not pressure forces as was used in option D).
The only correct option left is "A"
(a). the resultant force in the direction of the freestream velocity is termed the drag and the resultant force normal to the freestream velocity is termed the lift