There are two categories of ultraviolet light. Ultraviolet A ( UVA ) has a wavelength ranging from 320nm to 400nm . It is not so harmful to the skin and is necessary for the production of vitamin D. UVB, with a wavelength between 280nm and 320nm , is much more dangerous, because it causes skin cancer

PART A

Find the frequency ranges of UVA.

Enter your answers separated with commas.

fmin, fmax= 7.50

7.5 * 10^(14) Hz to 9.375 * 10^(14) Hz.

Explanation:

The minimum wavelength, λ₁ = 320 nm = 3.2 * 10⁻⁷ m

The corresponding frequency can be obtained by using the formula of speed of light:

c = λ₁ * f₁

f₁ = c / λ₁

f₁ = ( 3 * 10^8) / (3.2 * 10^(-7))

f₁ = 9.375 * 10^(14) Hz

The maximum wavelength, λ₂ = 400 nm = 4 * 10⁻⁷ m

The corresponding frequency can be obtained by using the formula of speed of light:

c = λ₂ * f₂

f₂ = c / λ₂

f₂ = ( 3 * 10^8) / (4 * 10^(-7))

f₂ = 7.5 * 10^(14) Hz

The frequency range of UVA is therefore 7.5 * 10^(14) Hz to 9.375 * 10^(14) Hz.

d. learned preferences i believe is your answer

explanation:

earth's surface is mainly heated by the absorption of infrared radiation from the sun.

evaporation occurs because molecules in liquid water are warmed ( usually by the sun) and vibrate quicker, becoming less dense and rise.

condensation occurs because molecules in water vapor are cooled and therefore vibrate more slowly thus becoming more dense and eventually fall to earth.

lines of equal barometric pressure on a weather map are called: isobars : lines of equal temp on a weather map are called: isotherms.​