You leave a light on in your house for 10 minutes (600 seconds). the lightbulb draws 0.5 amps at 120 volts. what is the power rating of the lightbulb and how much energy is consumed in the 10 minutes? a) 60 watts and 0.1 joules b) 60 watts and 36,000 joules c) 240 watts and 0.4 joules d) 2400 watts and 144,00 joules

> What is the power rating?

The power rating can actually be calculated by the product of current and volts. Therefore:

Power = I V

Given that current I = 0.5 A and V = 120 volts, therefore:

Power = (0.5 A) (120 V)

Power = 60 Watts

> How much energy is consumed in 10 minutes

Energy is simply the product of power and time in seconds, therefore:

Energy = Power * time

Energy = 60 Watts * (600 seconds)

Energy = 36,000 Joules

B

the total distance traveled by the car is

30km + 49km = 79 km .

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.