To find the internal energy of gas we can use
![U = \frac{f}{2}nRT](https://tex.z-dn.net/?f=U%20%3D%20%5Cfrac%7Bf%7D%7B2%7DnRT)
here given that
Number of moles (n) = 7 moles
Temperature T = 40 + 273 = 313 K
degree of freedom(f) = 5 (for diatomic gas)
now by above formula
![U = \frac{5}{2}* 7 * 8.31 * 313](https://tex.z-dn.net/?f=U%20%3D%20%5Cfrac%7B5%7D%7B2%7D%2A%207%20%2A%208.31%20%2A%20313)
![U = 45518.03 J](https://tex.z-dn.net/?f=U%20%3D%2045518.03%20J)
<em>So it is approximately 45500 J (option C)</em>
Given,
Weight of a block on the Earth = 980 N
Acceleration due to gravity on Earth = 9.8 N/kg
To find,
Weight of the block on the moon.
Solution,
The moon has acceleration (1/6) times that on earth. Let m be the mass of the block on the moon.
We know that,
W = mg
![m=\dfrac{W}{g}\\\\m=\dfrac{980}{9.8}\\\\=100\ kg](https://tex.z-dn.net/?f=m%3D%5Cdfrac%7BW%7D%7Bg%7D%5C%5C%5C%5Cm%3D%5Cdfrac%7B980%7D%7B9.8%7D%5C%5C%5C%5C%3D100%5C%20kg)
As mass of an object remains the same everywhere. Weight of the block on Moon is :
W' = mg'
As g'=(g/6)
So,
![W=100\times \dfrac{g}{6}\\\\=100\times \dfrac{9.8}{6}\\\\=163.33\ N](https://tex.z-dn.net/?f=W%3D100%5Ctimes%20%5Cdfrac%7Bg%7D%7B6%7D%5C%5C%5C%5C%3D100%5Ctimes%20%5Cdfrac%7B9.8%7D%7B6%7D%5C%5C%5C%5C%3D163.33%5C%20N)
So, the weight of the block on the moon is 163.33 N.
Answer:
C. In the direction that energy flows though the food chain
Explanation:
Strawberry > Cricket > Mouse > Owl. Energy is going this way
Answer:
The correct option is;
Why car engines are not perfectly efficient
Explanation:
The Second Law of Thermodynamics states that the total entropy, S, of a system combined with the entropy of its surrounding cannot be decreased, such that for an irreversible process, the entropy always increases and
>
, while for a reversible process the entropy is constant and ![S_f = S_i](https://tex.z-dn.net/?f=S_f%20%3D%20S_i)
The entropy is a measure of the amount of useful work obtainable from heat (or thermal) energy
A system with a low entropy has high amounts of heat energy capable of doing work while a high entropy system can produce only a small amount of useful work from the available thermal energy
In car engines, as the parts start to move, the entropy of the system increases alongside the generated heat lost to the environment, the amount of heat available for doing work reduces and therefore, the entropy increases further and the ratio of work obtainable from a given input of heat energy reduces and therefore, the car engine is not perfectly efficient.