Question 1

A small gas laser of the type used in classrooms may radiate light at a power level of 2.0 mW.If the wavelength of the laser light is 642 nm,how many photons does it emit per second? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Accepted Answer

The answer of A small gas laser of the type...

Question 2

Gamma rays are photons with very high energy.How many visible-light photons with a wavelength of 500 nm would you need to equal the energy of a gamma-ray photon with energy $4.1 \times 10^{ - 13} \mathrm {~J} ?$ A)1.0 × 10⁶ B)1.4 × 10⁸ C)6.2 × 10⁹ D)3.9 × 10³

Accepted Answer

The answer of Gamma rays are photons with very high...

Question 3

What is the photon energy of red light having a wavelength of 6.40 × 10² nm? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s) A)1.13 × 10^-¹⁹ J B)1.31 × 10^-19 J C)3.11 × 10^-19 J D)1.94 × 10^-19 J

Accepted Answer

We can use the formula E = hc/λ to find the energy of a photon with wavelength λ. 
Substituting the given values, we get:
E = (6.626 × 10^-34 J ∙ s)(3.00 × 10^8 m/s)/(6.40 × 10^-7 m)
E = 3.11 × 10^-19 J

Therefore, the photon energy of red light having a wavelength of 6.40 × 10^-7 nm is 3.11 × 10^-19 J. This matches with option C.

Question 4

An 84-kW AM radio station broadcasts at 1000 kHz.How many photons are emitted each second by the transmitting antenna? (h = 6.626 × 10^-34 J ∙ s) A)1.3 × $10^{32}$ B)2.9 × $10^{24}$ C)6.3 × $10^{12}$ D)1.4 × $10^{15}$

Accepted Answer

The number of photons emitted per second can be calculated using the formula: $$ \text{Number of photons} = \frac{\text{Power}}{\text{Energy per photon}} $$ where the energy per photon is given by $E = h \cdot f$, with $h$ being Planck's constant ($6.626 \times 10^{-34} \, \text{J} \cdot \text{s}$) and $f$ the frequency of the radio waves ($1000 \, \text{kHz} = 1 \times 10^6 \, \text{Hz}$). Thus, $$ E = 6.626 \times 10^{-34} \, \text{J} \cdot \text{s} \times 1 \times 10^6 \, \text{Hz} = 6.626 \times 10^{-28} \, \text{J} $$ The power of the radio station is $84 \, \text{kW} = 84 \times 10^3 \, \text{W}$, so the number of photons emitted per second is: $$ \frac{84 \times 10^3 \, \text{W}}{6.626 \times 10^{-28} \, \text{J}} \approx 1.3 \times 10^{32} $$ Therefore, the correct answer is $1.3 \times 10^{32}$ photons per second.

Question 5

If the longest wavelength of light that is able to dislodge electrons from a metal is 373 nm,what is the work function of that metal,in electron-volts? (1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Accepted Answer

The answer of If the longest wavelength of light that...

Question 6

A metal surface has a work function of 2.50 eV.What is the longest wavelength of light that will eject electrons from the surface of this metal? (1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Accepted Answer

The answer of A metal surface has a work function...

Question 7

The human eye can just detect green light of wavelength 500 nm if it arrives at the retina at the rate of 2 × 10^-18 W.How many photons arrive each second? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Accepted Answer

The answer of The human eye can just detect green...

Question 8

A laser emits a pulse of light that lasts 10 ns.The light has a wavelength of 690 nm,and each pulse has an energy of 480 mJ.How many photons are emitted in each pulse? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s) A)1.7 × 10¹⁸ B)2.1 × $10^{27}$ C)2.6 × $10^{37}$ D)3.1 × $10^{43}$

Accepted Answer

The number of photons in each pulse can be calculated using the energy of a single photon and the total energy of the pulse. The energy of a single photon is given by $E = \frac{hc}{\lambda}$, where $h$ is Planck's constant, $c$ is the speed of light, and $\lambda$ is the wavelength of the light. Substituting the given values, $h = 6.626 \times 10^{-34} \, \text{J} \cdot \text{s}$, $c = 3.0 \times 10^8 \, \text{m/s}$, and $\lambda = 690 \times 10^{-9} \, \text{m}$, we find the energy of a single photon. The total number of photons is then the total pulse energy divided by the energy of a single photon, $N = \frac{480 \times 10^{-3}}{E}$. Calculating with the given values leads to the correct order of magnitude as in option A.

Question 9

A helium-neon laser emits light at 632.8 nm.If the laser emits $1.82 \times 10^{17} $ photons/second,what is its power output in mW? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s) A)57.2 mW B)28.6 mW C)37.2 mW D)45.7 mW

Accepted Answer

The energy of a single photon is given by:$$E = hf = \frac{hc}{\lambda}$$where:* $h$ is Planck's constant* $f$ is the frequency of the light* $c$ is the speed of light* $\lambda$ is the wavelength of the lightThe power output of the laser is given by:$$P = N \times E$$where:* $N$ is the number of photons emitted per second* $E$ is the energy of a single photonSubstituting the given values into the equations above, we get:$$E = \frac{(6.626 \times 10^{-34} \text{ J} \cdot \text{s})(3.00 \times 10^8 \text{ m/s})}{632.8 \times 10^{-9} \text{ m}} = 3.14 \times 10^{-19} \text{ J}$$$$P = (1.82 \times 10^{17} \text{ photons/s})(3.14 \times 10^{-19} \text{ J/photon}) = 57.2 \text{ mW}$$Therefore, the power output of the laser is 57.2 mW.

Question 10

What is the energy (in eV)of an optical photon of frequency $6.43 \times 10 ^ { 14 } \mathrm {~Hz}$ (h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J) A)2.66 eV B)1.62 eV C)1.94 eV D)3.27 eV

Accepted Answer

The energy of a photon is given by:

E = hf

where h is the Planck's constant (6.626 × 10-34 J ∙ s) and f is the frequency of the photon.

Converting the frequency to Hz:

f = 6.43 × 1014 Hz

Plugging in the values:

E = hf = (6.626 × 10-34 J ∙ s) × (6.43 × 1014 Hz) = 4.26 × 10-19 J

Converting the energy to eV:

1 eV = 1.60 × 10-19 J

E = (4.26 × 10-19 J) / (1.60 × 10-19 J/eV) = 2.66 eV

Therefore, the energy of the optical photon is 2.66 eV, which corresponds to choice A.

Question 11

A photoelectric surface has a work function of 2.10 eV.Calculate the maximum kinetic energy,in eV,of electrons ejected from this surface by electromagnetic radiation of wavelength 356 nm.(1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Accepted Answer

The answer of A photoelectric surface has a work function...

Question 12

What frequency of electromagnetic radiation has photons of energy 4.7 × 10^-25 J? (h = 6.626 × 10^-34 J ∙ s) A)710 kHz B)4.7 MHz C)710 MHz D)1.4 GHz

Accepted Answer

The energy of a photon is calculated by the equation E = hf, where E is energy, h is Planck's constant, and f is frequency.
Rearranging this equation to solve for frequency, we get f = E/h.
Plugging in the given values, we get f = (4.7 × 10^-25 J) / (6.626 × 10^-34 J∙s) = 7.10 × 10^14 Hz = 710 MHz.
Therefore, the correct choice is C.

Question 13

Each photon in a beam of light has an energy of 4.20 eV.What is the wavelength of this light? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J) A)321 nm B)103 nm C)296 nm D)412 nm E)420 nm

Accepted Answer

The energy of a photon is given by $E = hc/\lambda$, where $h$ is Planck's constant, $c$ is the speed of light, and $\lambda$ is the wavelength of light. Rearranging the equation to solve for $\lambda$, we have $\lambda = hc/E$. 
Substituting the given values, we have $\lambda = (6.626	imes10^{-34}	ext{ J}\cdot	ext{s})(3.00	imes10^8	ext{ m/s})/(4.20	imes1.60	imes10^{-19}	ext{ J}) \approx 296	ext{ nm}$. 
Therefore, the best choice is (C).

Question 14

What is the wavelength of a photon having energy 2.00 eV? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J)

Accepted Answer

The answer of What is the wavelength of a photon...

Question 15

A metallic surface is illuminated with light of wavelength 400 nm.If the work function for this metal is 2.40 eV,what is the maximum kinetic energy of the ejected electrons,in electron-volts? (1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Accepted Answer

The answer of A metallic surface is illuminated with light...

Question 16

Gamma rays are photons with very high energy.What is the wavelength of a gamma-ray photon with energy 7.7 × 10^-13 J? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s) A)2.6 × 10^-13 m B)3.9 × 10^-13 m C)3.1 × 10^-13 m D)3.5 × 10^-13 m

Accepted Answer

The answer of Gamma rays are photons with very high...

Question 17

What is the wavelength of a 6.32-eV photon? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19J) A)197 nm B)167 nm C)216 nm D)234 nm

Accepted Answer

The wavelength of a photon can be calculated using the formula λ = hc/E, where h is Planck's constant, c is the speed of light, and E is the energy of the photon. First, convert the energy from eV to Joules: 6.32 eV * 1.60 × 10^-19 J/eV = 1.0112 × 10^-18 J. Then, λ = (6.626 × 10^-34 J·s * 3.00 × 10^8 m/s) / 1.0112 × 10^-18 J ≈ 1.97 × 10^-7 m or 197 nm.

Question 18

A laser pulse of duration 25 ms has a total energy of 1.4 J.If the wavelength of this radiation is 567 nm,how many photons are emitted in one pulse? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s) A)4.0 × 10¹⁸ B)9.9 × 10¹⁹ C)4.8 × 10¹⁹ D)1.6 × 10¹⁷ E)3.2 × 10¹⁷

Accepted Answer

The answer of A laser pulse of duration 25 ms...

Question 19

For what wavelength does a 100-mW laser beam deliver 1.6 × 10¹⁷ photons in one second? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s) A)320 nm B)330 nm C)340 nm D)350 nm

Accepted Answer

The answer of For what wavelength does a 100-mW laser...

Question 20

How much energy is carried by a photon of light having frequency 110 GHz? (h = 6.626 × 10^-34 J ∙ s) A)1.1 × 10^-20 J B)1.4 × 10^-22 J C)7.3 × 10^-23 J D)1.3 × 10^-25 J

Accepted Answer

The answer of How much energy is carried by a...

Quiz 27: Quantum Optics

A small gas laser of the type used in classrooms may radiate light at a power level of 2.0 mW.If the wavelength of the laser light is 642 nm,how many photons does it emit per second? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Gamma rays are photons with very high energy.How many visible-light photons with a wavelength of 500 nm would you need to equal the energy of a gamma-ray photon with energy $4.1 \times 10^{ - 13} \mathrm {~J} ?$

What is the photon energy of red light having a wavelength of 6.40 × 10² nm? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

An 84-kW AM radio station broadcasts at 1000 kHz.How many photons are emitted each second by the transmitting antenna? (h = 6.626 × 10^-34 J ∙ s)

If the longest wavelength of light that is able to dislodge electrons from a metal is 373 nm,what is the work function of that metal,in electron-volts? (1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

A metal surface has a work function of 2.50 eV.What is the longest wavelength of light that will eject electrons from the surface of this metal? (1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

The human eye can just detect green light of wavelength 500 nm if it arrives at the retina at the rate of 2 × 10^-18 W.How many photons arrive each second? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

A laser emits a pulse of light that lasts 10 ns.The light has a wavelength of 690 nm,and each pulse has an energy of 480 mJ.How many photons are emitted in each pulse? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

A helium-neon laser emits light at 632.8 nm.If the laser emits $1.82 \times 10^{17}$ photons/second,what is its power output in mW? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

What is the energy (in eV) of an optical photon of frequency $6.43 \times 10 ^ { 14 } \mathrm {~Hz}$ (h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J)

A photoelectric surface has a work function of 2.10 eV.Calculate the maximum kinetic energy,in eV,of electrons ejected from this surface by electromagnetic radiation of wavelength 356 nm.(1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

What frequency of electromagnetic radiation has photons of energy 4.7 × 10^-25 J? (h = 6.626 × 10^-34 J ∙ s)

Each photon in a beam of light has an energy of 4.20 eV.What is the wavelength of this light? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J)

What is the wavelength of a photon having energy 2.00 eV? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J)

A metallic surface is illuminated with light of wavelength 400 nm.If the work function for this metal is 2.40 eV,what is the maximum kinetic energy of the ejected electrons,in electron-volts? (1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Gamma rays are photons with very high energy.What is the wavelength of a gamma-ray photon with energy 7.7 × 10^-13 J? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

What is the wavelength of a 6.32-eV photon? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19J)

A laser pulse of duration 25 ms has a total energy of 1.4 J.If the wavelength of this radiation is 567 nm,how many photons are emitted in one pulse? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

For what wavelength does a 100-mW laser beam deliver 1.6 × 10¹⁷ photons in one second? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

How much energy is carried by a photon of light having frequency 110 GHz? (h = 6.626 × 10^-34 J ∙ s)

Quiz 27: Quantum Optics

A small gas laser of the type used in classrooms may radiate light at a power level of 2.0 mW.If the wavelength of the laser light is 642 nm,how many photons does it emit per second? (c = 3.0 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

Gamma rays are photons with very high energy.How many visible-light photons with a wavelength of 500 nm would you need to equal the energy of a gamma-ray photon with energy 4.1×10−13 J?4.1 \times 10^{ - 13} \mathrm {~J} ?4.1×10−13 J?

What is the photon energy of red light having a wavelength of 6.40 × 102 nm? (c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

An 84-kW AM radio station broadcasts at 1000 kHz.How many photons are emitted each second by the transmitting antenna? (h = 6.626 × 10-34 J ∙ s)

If the longest wavelength of light that is able to dislodge electrons from a metal is 373 nm,what is the work function of that metal,in electron-volts? (1 eV = 1.60 × 10-19 J,c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

A metal surface has a work function of 2.50 eV.What is the longest wavelength of light that will eject electrons from the surface of this metal? (1 eV = 1.60 × 10-19 J,c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

The human eye can just detect green light of wavelength 500 nm if it arrives at the retina at the rate of 2 × 10-18 W.How many photons arrive each second? (c = 3.0 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

A laser emits a pulse of light that lasts 10 ns.The light has a wavelength of 690 nm,and each pulse has an energy of 480 mJ.How many photons are emitted in each pulse? (c = 3.0 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

A helium-neon laser emits light at 632.8 nm.If the laser emits 1.82×10171.82 \times 10^{17} 1.82×1017 photons/second,what is its power output in mW? (c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

What is the energy (in eV) of an optical photon of frequency 6.43×1014 Hz6.43 \times 10 ^ { 14 } \mathrm {~Hz}6.43×1014 Hz (h = 6.626 × 10-34 J ∙ s,1 eV = 1.60 × 10-19 J)

A photoelectric surface has a work function of 2.10 eV.Calculate the maximum kinetic energy,in eV,of electrons ejected from this surface by electromagnetic radiation of wavelength 356 nm.(1 eV = 1.60 × 10-19 J,c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

What frequency of electromagnetic radiation has photons of energy 4.7 × 10-25 J? (h = 6.626 × 10-34 J ∙ s)

Each photon in a beam of light has an energy of 4.20 eV.What is the wavelength of this light? (c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s,1 eV = 1.60 × 10-19 J)

What is the wavelength of a photon having energy 2.00 eV? (c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s,1 eV = 1.60 × 10-19 J)

A metallic surface is illuminated with light of wavelength 400 nm.If the work function for this metal is 2.40 eV,what is the maximum kinetic energy of the ejected electrons,in electron-volts? (1 eV = 1.60 × 10-19 J,c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

Gamma rays are photons with very high energy.What is the wavelength of a gamma-ray photon with energy 7.7 × 10-13 J? (c = 3.0 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

What is the wavelength of a 6.32-eV photon? (c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s,1 eV = 1.60 × 10-19 J)

A laser pulse of duration 25 ms has a total energy of 1.4 J.If the wavelength of this radiation is 567 nm,how many photons are emitted in one pulse? (c = 3.00 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

For what wavelength does a 100-mW laser beam deliver 1.6 × 1017 photons in one second? (c = 3.0 × 108 m/s,h = 6.626 × 10-34 J ∙ s)

How much energy is carried by a photon of light having frequency 110 GHz? (h = 6.626 × 10-34 J ∙ s)

A small gas laser of the type used in classrooms may radiate light at a power level of 2.0 mW.If the wavelength of the laser light is 642 nm,how many photons does it emit per second? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Gamma rays are photons with very high energy.How many visible-light photons with a wavelength of 500 nm would you need to equal the energy of a gamma-ray photon with energy $4.1 \times 10^{ - 13} \mathrm {~J} ?$

What is the photon energy of red light having a wavelength of 6.40 × 10² nm? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

An 84-kW AM radio station broadcasts at 1000 kHz.How many photons are emitted each second by the transmitting antenna? (h = 6.626 × 10^-34 J ∙ s)

If the longest wavelength of light that is able to dislodge electrons from a metal is 373 nm,what is the work function of that metal,in electron-volts? (1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

A metal surface has a work function of 2.50 eV.What is the longest wavelength of light that will eject electrons from the surface of this metal? (1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

The human eye can just detect green light of wavelength 500 nm if it arrives at the retina at the rate of 2 × 10^-18 W.How many photons arrive each second? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

A laser emits a pulse of light that lasts 10 ns.The light has a wavelength of 690 nm,and each pulse has an energy of 480 mJ.How many photons are emitted in each pulse? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

A helium-neon laser emits light at 632.8 nm.If the laser emits $1.82 \times 10^{17}$ photons/second,what is its power output in mW? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

What is the energy (in eV) of an optical photon of frequency $6.43 \times 10 ^ { 14 } \mathrm {~Hz}$ (h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J)

A photoelectric surface has a work function of 2.10 eV.Calculate the maximum kinetic energy,in eV,of electrons ejected from this surface by electromagnetic radiation of wavelength 356 nm.(1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

What frequency of electromagnetic radiation has photons of energy 4.7 × 10^-25 J? (h = 6.626 × 10^-34 J ∙ s)

Each photon in a beam of light has an energy of 4.20 eV.What is the wavelength of this light? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J)

What is the wavelength of a photon having energy 2.00 eV? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19 J)

A metallic surface is illuminated with light of wavelength 400 nm.If the work function for this metal is 2.40 eV,what is the maximum kinetic energy of the ejected electrons,in electron-volts? (1 eV = 1.60 × 10^-19 J,c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

Gamma rays are photons with very high energy.What is the wavelength of a gamma-ray photon with energy 7.7 × 10^-13 J? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

What is the wavelength of a 6.32-eV photon? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,1 eV = 1.60 × 10^-19J)

A laser pulse of duration 25 ms has a total energy of 1.4 J.If the wavelength of this radiation is 567 nm,how many photons are emitted in one pulse? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

For what wavelength does a 100-mW laser beam deliver 1.6 × 10¹⁷ photons in one second? (c = 3.0 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

How much energy is carried by a photon of light having frequency 110 GHz? (h = 6.626 × 10^-34 J ∙ s)