Question

Ultraviolet light A (UVA) can penetrate deeper layers of skin than UVB. If UVA has a wavelength of 400 nm, how much energy would be in this wave? 2 x 10-17)​

Answer 1

Answer:

E = 5×10⁻¹⁹ J

Explanation:

Given data:

Wavelength = 400 nm (400×10⁻⁹ m)

Energy of wave = ?

Solution:

Formula:

E = h c/λ

c = 3×10⁸ m/s

h = 6.63×10⁻³⁴ Js

Now we will put the values in formula.

E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s /400×10⁻⁹ m

E = 19.89×10⁻²⁶ J.m / 400×10⁻⁹ m

E = 0.05×10⁻¹⁷ J

E = 5×10⁻¹⁹ J