1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
CaHeK987 [17]
3 years ago
11

An electron has a kinetic energy of 3.00 ev. find its wavelength. (b) what if? a photon has energy 3.00 ev. find its wavelength.

Physics
1 answer:
Harman [31]3 years ago
8 0
(a) The electron kinetic energy is
K=3.00 eV
which can be converted into Joule by keeping in mind that
1 eV=1.6 \cdot 10^{-19}eV
So that we find
K=3.00 eV \cdot 1.6 \cdot 10^{-19} eV/J =4.8 \cdot 10^{-19}J

The kinetic energy of the electron is related to its momentum p by:
K= \frac{p^2}{2m}
where m is the electron mass. Re-arranging the equation, we find
p= \sqrt{ 2Km}= \sqrt{ 2  ( 4.8 \cdot 10^{-19} J)(9.1 \cdot 10^{-31} kg) } =9.35 \cdot 10^{-25} kgm/s

And now we can use De Broglie's relationship to find its wavelength:
\lambda= \frac{h}{p}= \frac{6.6 \cdot 10^{-34} Js}{9.35 \cdot 10^{-25} kg m/s} =7.06 \cdot 10^{-10}m
where h is the Planck constant.


(b) By using the same procedure of part (a), we can convert the photon energy into Joules:
E=3.00 eV \cdot 1.6 \cdot 10^{-19} eV/J =4.8 \cdot 10^{-19}J

The energy of a photon is related to its frequency f by:
E=hf
where h is the Planck constant. Re-arranging the equation, we find
f= \frac{E}{h}= \frac{4.8 \cdot 10^{-19} J}{6.6 \cdot 10^{-34}Js} =7.27 \cdot 10^{14}Hz

And now we can use the relationship between frequency f, speed of light c and wavelength \lambda of a photon, to find its wavelength:
\lambda= \frac{c}{f}= \frac{3 \cdot 10^8 m/s}{7.27 \cdot 10^{14} Hz} =4.13 \cdot 10^{-7} m
You might be interested in
What is the speed of gravity
mojhsa [17]
9.8m per seccond is the speed of gravity if you drop something like a ball from a tower
8 0
3 years ago
If a 375 watt heater has a current of 5.0 A, what is the resistance of the heating element?
liberstina [14]
P=IV
V=IR

P=I(IR)
P=I²R
375=5²R
R=375/25
R=15
7 0
3 years ago
Light does not move infinitely fast but has a finite speed. We normally use ""c"" to indicate the speed of light in science. Wri
Ede4ka [16]

Answer:

6.71 × 10^8 mi/hr

Explanation:

Light is usually defined as an electromagnetic wave that is comprised of a definite wavelength. It is of both types, visible and invisible. The light emitted from a source usually travels at a speed of about 3 × 10^8 meter/sec. This speed of light is commonly represented by the letter 'C'.

To write it in the metric system, it has to be converted into miles/hour.

We know that,

1 minute = 60 seconds

60 minutes = 1 hour

1 kilometer = 1000 meter

1 miles = 1.6 kilometer

Now,

= \frac{3 \times\ 10^8 meter \times\ 60 sec \times\ 60 min}{1 sec \times\ 1 min \times\ 1 hr}

= 1.08 × 10^12 m/ hr (meter/hour)

= \frac{1.08 \times\ 10^{12} meter \times\ 1 km \times\ 1 miles}{1 hr \times\ 1000 meter \times\ 1.6 km}

= 6.71 × 10^8 mi/hr (miles/hour)

Thus, the value for speed of light (C) in metric unit is 6.71 × 10^8 mi/hr.

5 0
3 years ago
Mengapa indra peraba tidak dapat digunakan untuk membandingkan suhu dengan tepat?
Debora [2.8K]
Answer it ur self if u have internet
3 0
3 years ago
A vehicle moving with a uniform a acceleration of 2m/s and has a velocity of 4m/s at a certain time .
Evgesh-ka [11]

Answer:

1 second later the vehicle's velocity will be:

v(1)= 6\,\,\frac{m}{s} \\

5 seconds later the vehicle's velocity will be:

v(5)=14\,\,\frac{m}{s}

Explanation:

Recall the formula for the velocity of an object under constant accelerated motion (with acceleration "a"):

v(t)=v_0+a\,t

Therefore, in this case v_0=4\,\,\frac{m}{s}  and a=2\,\,\frac{m}{s^2}

so we can estimate the velocity of the vehicle at different times just by replacing the requested "t" in the expression:

v(t)=v_0+a\,t\\v(t)=4+2\,\,t\\v(1)=4+2\,(1) = 6\,\,\frac{m}{s} \\v(5)=4+2\,(5)=14\,\,\frac{m}{s}

3 0
3 years ago
Other questions:
  • Which of the following is an example of a rotating body?
    15·2 answers
  • He<br> Fill in the blanks<br> - If two<br> objects are brought close together,<br> happens.
    6·1 answer
  • What is the energy of a photon of blue light with a wavelength of 460 nm?
    12·1 answer
  • An object in motion will stay in motion unless acted upon by what type of force?​
    6·1 answer
  • The distance between Neptune and the Sun is 30.06 AU. What is this distance in millions of kilometers? (One AU is about 150 mill
    10·2 answers
  • Hey what is Krichoff rule<br>good morning​
    13·2 answers
  • A ball is dropped from the roof of a building. Points A, B, C, and D in the diagram below represent positions of the ball as it
    5·1 answer
  • What was the orginal purpose of the constitutional convention and what conclusion did they quickly came to?
    5·1 answer
  • an airplane is moving at a speed of 75 m/s. as it. lands on a. runwsys. if. the runway is. 500m long, what is the acceleration o
    11·1 answer
  • 1. Is the image projected on a movie screen real or virtual? What about the image of yourself seen in a bathroom mirror?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!