Answer:
The correct option is;
(c) 64W
Explanation:
Here we have the Coefficient Of Performance, COP given by
The heat change from 23° to 6°C for a mass of 10 kg/h which is equivalent to 10/(60×60) kg/s or 2.78 g/s we have
= m·c·ΔT = 2.78 × 4.18 × (23 - 6) = 197.39 J
Therefore, plugging in the value for in the COP equation we get;
which gives
Since we were working with mass flow rate then the power input is the same as the work done per second and the power input to the refrigerator = 63.674 J/s ≈ 64 W.
The power input to the refrigerator is approximately 64 W.
Complete Question
Use Stefan's law to find the intensity of the cosmic background radiation emitted by the fireball of the Big Bang at a temperature of 2.81 K. Remember that Stefan's Law gives the Power (Watts) and Intensity is Power per unit Area (W/m2).
Answer:
The intensity is 
Explanation:
From the question we are told that
The temperature is 
Now According to Stefan's law
Where 
is the Stefan Boltzmann constant with value 
Now the intensity of the cosmic background radiation emitted according to the unit from the question is mathematically evaluated as
=> 
=> 
substituting values
Watchglass is a lab equipment that is used as a cover to prevent heated materials from splattering out of the container and as a holding plate for hot or flammable materials
<u>Explanation:</u>
Watch glass is an equipment used as a cover to prevent heated materials from splattering out of the container and as a holding plate for hot or flammable materials. It is a kind of concave glass which is also used to evaporate a liquid and also provides good air circulation which is used during cooking. The name watchglass was derived as they are see through and so similar to pocket glasses.
