A40-l electrical radiator containing heating oil is placed in a 50-m3 room as shown in the figure. both the room and the oil in the radiator are initially at 10°c. the radiator with a rating of 2.4 kw is now turned on. at the same time, heat is lost from the room at an average rate of 0.35 kj/s. after some time, the average temperature is measured to be 20°c for the air in the room, and 50°c for the oil in the radiator. taking the density and the specific heat of the oil to be 950 kg/m3 and 2.2 kj/kg·°c, respectively, determine how long the heater is kept on. assume the room is well-sealed so that there are no air leaks. the gas constant of air is r = 0.287 kpa. m3/kg. k. also, cv = 0.718 kj/kg. k for air at room temperature. oil properties are given to be ρ = 950 kg/m3 and cp = 2.2 kj/kg.°c. (round the final answer to one decimal place.)

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.

i think the answer is tomato juice? not entirely sure though