Answer:
d) -4.0
Explanation:
The magnification of a lens is given by
![M=-\frac{q}{p}](https://tex.z-dn.net/?f=M%3D-%5Cfrac%7Bq%7D%7Bp%7D)
where
M is the magnification
q is the distance of the image from the lens
p is the distance of the object from the lens
In this problem, we have
p = 50 cm is the distance of the object from the lens
q = 250 cm - 50 cm is the distance of the image from the lens (because the image is 250 cm from the obejct
Also, q is positive since the image is real
So, the magnification is
![M=-\frac{200 cm}{50 cm}=-4.0](https://tex.z-dn.net/?f=M%3D-%5Cfrac%7B200%20cm%7D%7B50%20cm%7D%3D-4.0)
My best guess is c) Dark colors reflect less radiation making them warmer.
hope this helps!
2 pounds = 9 burgers figure out ow many 9's you can get out of 100: 100/9=11 but that only makes 99 you need 100 so we would add another one making 12. now multiply 12 by 2: 12·2=24. You would need 24 pounds of meet :)
As per energy conservation in the reversible engine we can say
![Q_2 + W = Q_1](https://tex.z-dn.net/?f=Q_2%20%2B%20W%20%3D%20Q_1)
here we know that
![Q_2 = 3300 kJ/h](https://tex.z-dn.net/?f=Q_2%20%3D%203300%20kJ%2Fh)
![Q_1 = 4800 kJ/h](https://tex.z-dn.net/?f=Q_1%20%3D%204800%20kJ%2Fh)
now from above equation
![3300 + W = 4800](https://tex.z-dn.net/?f=3300%20%2B%20W%20%3D%204800)
![W = 1500 kJ/h](https://tex.z-dn.net/?f=W%20%3D%201500%20kJ%2Fh)
now we can convert it into kW
![W = 1500\times \frac{kJ}{3600s}](https://tex.z-dn.net/?f=W%20%3D%201500%5Ctimes%20%5Cfrac%7BkJ%7D%7B3600s%7D)
![W = 0.42 kW](https://tex.z-dn.net/?f=W%20%3D%200.42%20kW)
so above is the power input to the refrigerator
now to find COP we know that
![COP = \frac{Q_2}{W}](https://tex.z-dn.net/?f=COP%20%3D%20%5Cfrac%7BQ_2%7D%7BW%7D)
![COP = \frac{3300}{1500} = 2.2](https://tex.z-dn.net/?f=COP%20%3D%20%5Cfrac%7B3300%7D%7B1500%7D%20%3D%202.2)
so COP of refrigerator is 2.2