Red light with a wavelength of 725 nm shines through a single slit, and forms a pattern on a screen placed 1.25 m away. if the width of the slit is 18.5 micrometers, find the width of the central maximum

(a) in degrees and (b) in centimeters

(a) 4.5°     (b) 9.8 cm

Explanation:

Given:

λ = 725*10^(-9) m

d = 18.5*10^(-3) m

L = 1.25 m

Let θ₁ be the first minimum and is equal to = λ /d

= 725*10^(-9)/18.5*10^(-6)

= 0.0392

= 0.0392

In view of smallness of this number, we have sin θ₁ = θ₁ = 0.0392

The angular width of the central maximum θm is twice the first minimum.

so θm = θ₁ = 2*0.0392 = 0.0784

The angular width in degrees is then 360*θm/2π = 4.5°. The width in centimetres is proportional to the distance to the screen (L = 125 cm) and is given approximately by θm*L = 0.0784*125 = 9.8 cm

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.

spectral lines lyman is one set