Answer:
best explanation of this is sentence B
Explanation:
The radiation emission of the bodies is given by the expression
P = σ A e T⁴
Where P is the power emitted in watts, σ is the Stefan-Boltzmann constant, A is the surface area of the body, e is the emissivity for black body e = 1 and T is the absolute body temperature in degrees Kelvin.
When the values are substituted the power is quite high 2.5 KW, but the medium surrounding the box also emits radiation
T box ≈ T room
P box ≈ P room
As the two powers are similar and the box can absorbed, since it has the ability to emit and absorb radiation, as the medium is also close of the temperature of the box, the amount emitted is very similar to that absorbed, so the net change in energy is very small.
In the case that the box is much hotter or colder than the surrounding medium if there is a significant net transfer.
Consequently, the best explanation of this is sentence B
Explanation:
Drinking water requirement in town 2.0 m^3/s of water per second
nitrate in local well nitrate per 15
of water
nitrate in distant reservoir 
Let the flow rate of well
flow rate of reservoir 
Drinking water requirement is
or 
therefore, the total flow of drinking water
Answer:
efficiency of solar panel is 18%
Explanation:
Energy received by the sunlight is given as

here we know the dimensions of the plate as


now we have


now the power received by the sun light is given as

now the output power due to solar panel is given as



now the efficiency is given as



Answer:
9375 N
Explanation:
From the question,
Centripetal force (F) = mv²/r.................. Equation 1
Where m = mass of the car, v = velocity of the car, r = radius of the curve.
Given: m = 900 kg, r = 600 m, v = 25 m/s
Substitute these values into equation 1
F = (900×25²)/600
F = 9375 N.
Hence the centripetal force on the car is 9375 N