Chapter 29, Problem 82PE

### College Physics

1st Edition
Paul Peter Urone + 1 other
ISBN: 9781938168000

Chapter
Section

### College Physics

1st Edition
Paul Peter Urone + 1 other
ISBN: 9781938168000
Textbook Problem

# Integrated ConceptsA laser with a power output of 2.00 mW at a wavelength of 400 nm is projected onto calcium metal. (a) How many electrons per second are ejected? (b) What power is carried away by the electrons, given that the binding energy is 2.71 eV? (c) Calculate the current of ejected electrons. (d) If the photoelectric material is electrically insulated and acts like a 2.00-pF capacitor, how long will current flow before the capacitor voltage stops it?

To determine

(a)

A laser with a power output of2.00mW at a wavelength of400nm is projected onto calcium metal. Find the number of electrons ejected per second

Explanation

Given Data:

Given that a laser with a power output of2.00mW at a wavelength of400nm is projected onto calcium metal.

Formula Used:

Energy of photon is calculated as

E=hcÎ»

Whereh= Planck's constant

c= Speed of light

Î»= Wavelength

Number of photons ejected per second is given as

Nt=PE

WhereNt= Number of protons ejected per second

E= Energy of photons

P= Power output

Calculation:

We haveÎ»=400nm

â€ƒâ€ƒc=3.00Ã—108m/s

â€ƒâ€ƒh=6.63Ã—10âˆ’34kg.m/s

Energy of photon is calculated as follows:

E=hcÎ»

Substituting the values in the above equation, we get

E=(6.63Ã—10âˆ’34kg.m/s)(3

To determine

(b)

A laser with a power output of2.00mW at a wavelength of400nm is projected onto calcium metal. The number of electrons ejected per second is4.03×1015 .What power is carried away by the electrons, given that the binding energy is2.71eV

To determine

(c)

A laser with a power output of2.00mW at a wavelength of400nm is projected onto calcium metal. The number of electrons ejected per second is4.03×1015 .The binding energy is2.71eV and the power carried away by the electrons is2.55×104W . Calculate the current of ejected electrons.

To determine

(d)

How long will current flow before the capacitor voltage stops it?

### Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

#### The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started