UV rays have the lowest energy, (highest wavelengths)
Answer:
<u>The correct answer is 0.556 Watts</u>
Explanation:
The computer monitor uses 200 Watts of power in an hour, that is the standard measure.
If we want to know, how much energy the computer monitor uses in one second, we will have to divide both sides of the equation into 3,600.
1 hour = 60 minutes = 3,600 seconds (60 x 60)
Energy per second = 200/3600
Energy per second = 0.0556 Watts
Therefore to calculate how much energy is used in 10 seconds, we do this:
Energy per second x 10
<u>0.0556 x 10 = 0.556 Watts</u>
<u>The computer monitor uses 0.556 Watts in 10 seconds</u>
The answer is to this question is B
Answer:
λ = 102.78 nm
This radiation is in the UV range,
Explanation:
Bohr's atomic model for the hydrogen atom states that the energy is
E = - 13.606 / n²
where 13.606 eV is the ground state energy and n is an integer
an atom transition is the jump of an electron from an initial state to a final state of lesser emergy
ΔE = 13.606 (1 /
- 1 / n_{i}^{2})
the so-called Lyman series occurs when the final state nf = 1, so the second line occurs when ni = 3, let's calculate the energy of the emitted photon
DE = 13.606 (1/1 - 1/3²)
DE = 12.094 eV
let's reduce the energy to the SI system
DE = 12.094 eV (1.6 10⁻¹⁹ J / 1 ev) = 10.35 10⁻¹⁹ J
let's find the wavelength is this energy, let's use Planck's equation to find the frequency
E = h f
f = E / h
f = 19.35 10⁻¹⁹ / 6.63 10⁻³⁴
f = 2.9186 10¹⁵ Hz
now we can look up the wavelength
c = λ f
λ = c / f
λ = 3 10⁸ / 2.9186 10¹⁵
λ = 1.0278 10⁻⁷ m
let's reduce to nm
λ = 102.78 nm
This radiation is in the UV range, which occurs for wavelengths less than 400 nm.