Astudent in an undergraduate physics lab is studying archimede's principle of bouyancy. the student is given a brass cylinder and, using a triple beam balance, finds the mass to be 3.21 kg. the density of this particular alloy of brass is 8.62 g/cm 3 . the student ties a massless string to one end of the cylinder and submerges it into a tank of water where there is an apparent reduction in the weight of the cylinder. with this information, calculate the volume, v , of the cylinder and the tension, t , in the string when it is submerged in the tank of water. the density of water is 1.00 g/cm 3 , and the acceleration due to gravity is gvolume of the cylinder: cm3tension in the string: n

V = 0.3724 m³

T = 27.836 N

Explanation:

Given :

m = 3.21 kg  , W= 3.21 * 9.81 m / s² = 31.4901 N

ρ = 8.62 g / cm ³  = 8620 kg / m³

V = m / ρ =  3.21 kg  /  8620 kg / m³

V = 0.3724 m³

when submerged the weight of brass cylinder is equal to the tension in string:

F =  (0.3724m³) * (1000 kg / m³) * (9.81 m/s²²) = 3.653 ≈ 3.65 N

T = 31.4901 N - 3.65 N  

T = 27.836 N

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.