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
finlep [7]
3 years ago
8

Biologists use optical tweezers to manipulate micron-sized objects using a beam of light. In this technique, a laser beam is foc

used to a very small-diameter spot. Because small particles are attracted to regions of high light intensity, the focused beam can be used to "grab" onto particles and manipulate them for various experiments. In one experiment, a 10 mW laser beam is focused to a spot that has a diameter of 0.67 μm
Part A: What is the intensity of the light in this spot?

Part B: What is the amplitude of the electric field?
Physics
1 answer:
vekshin13 years ago
8 0

Answer:

Explanation:

Part A) Using

light intensity I= P/A

A= Area= π (Radius)^2= π((0.67*10^-6m)/(2))^2= 1.12*10^-13 m^2

Radius= Diameter/2

P= power= 10*10^-3=0.01 W

light intensity I= 0.01/(1.12*10^-13)= 9*10^10 W/m^2

Part B)  Using

I=c*ε*E^2/2

rearrange to solve for E= \sqrt{((I*2)/(c*ε))

c is the speed of light which is 3*10^8 m/s^2

ε=permittivity of free space or dielectric constant= 8.85* 10^-12 F⋅m−1

I= the already solved light intensity= 8.85*10^10 W/m^2

amplitude of the electric field E= \sqrt{(9*10^10 W/m^2)*(2) / (3*10^8 m/s^2)*(8.85* 10^-12 F⋅m−1)

---> E= \sqrt{(1.8*10^11) / (2.66*10^-3) = \sqrt{(6.8*10^13) = 8.25*10^6 V/m    

 

You might be interested in
A child and sled with a combined mass of 50.0 kg slide down a frictionless slope. if the sled starts from rest and has a speed o
Furkat [3]
            <span> Using conservation of energy

Potential Energy (Before) = Kinetic Energy (After)

mgh = 0.5mv^2

divide both sides by m

gh = 0.5v^2

h = (0.5V^2)/g

h = (0.5*2.2^2)/9.81

h = 0.25m

</span>
4 0
2 years ago
Read 2 more answers
I need help in physics, pls hurry! I will give Brainliest for correct answers!!
Nana76 [90]
Top left: slowing down
Top right: not moving
Bottom left: moving at a constant speed
Bottom right: speeding up
6 0
2 years ago
Plz help..During takeoff a plane accelerates at 4m/s^2 and takes 40s to reach takeoff speed.
matrenka [14]

Answer:

The velocity of the plane at take off is 160 m/s.

The distance travel by the plane in that time is 3200 meter.

Explanation:

Given:

Acceleration, a = 4 m/s²

Time, t = 40 s

u = 0 i .e initial velocity

To Find:

velocity , v = ?

distance , s =?

Solution:

we have first Kinematic equation

v = u + at

∴ v = 0 + 4×40

∴ v = 160 m/s

Now by Third Kinematic equation

s = ut + \frac{1}{2}at^{2}

∴ s = 0 + 0.5 × 4× 40²

∴ s = 3200 meter

3 0
3 years ago
The Capacitive reactance of a 0.094uF capacitor when a frequency of 25kHz is applied is lus 68 Ohms 0.68 Ohms luf
Nana76 [90]

Answer:

Capacitive reactance of the capacitor is 68 ohms

Explanation:

It is given that,

Capacitance, C=0.094\ \mu F=0.094\times 10^{-6}\ F

Frequency, f=25\ kHz=25\times 10^3\ Hz

Capacitive reactance is given by :

X_C=\dfrac{1}{2\pi fC}

X_C=\dfrac{1}{2\pi 25\times 10^3\times 0.094\times 10^{-6}}

X_C=67.72\ \Omega

or

X_C=68\ \Omega

So, the capacitive reactance of the capacitor is 68 ohms. Hence, this is the required solution.

8 0
2 years ago
What did you learn from organize Notes, write 2 to 3 paragraphs explaining how that process is designed to help with your learni
Setler79 [48]

Answer:

yo ni siquiera he leido Organizar Notes y quisiera responderte pero el sistema no me deja escribir bien se esta alocando

Explanation:

5 0
3 years ago
Other questions:
  • On a Saturday afternoon, you decide to pay a neighborhood kid to mow your lawn. The kid usesa manual push lawn mower with a mass
    15·1 answer
  • In each case, a charged rod, made of the dense rubber ebonite, comes close or is in contact with the top of an electroscope. The
    11·2 answers
  • Each water molecule is joined to _____ other water molecules by ____ bonds.
    14·2 answers
  • In the stream, water waves bunched up as the water flowed by. As we
    10·1 answer
  • A constant torque of 26.6 N · m is applied to a grindstone for which the moment of inertia is 0.162 kg · m2 . Find the angular s
    14·2 answers
  • What will change the velocity of a periodic wave?
    10·2 answers
  • Both X-rays and gamma rays have higher frequencies than ultraviolet rays <br> True or False
    10·2 answers
  • How does a resistor affect an electrical circuit?
    14·2 answers
  • Engineers at the Space Centre must determine the net force needed for a rockets engine to achieve an acceleration of 70 m/s2. As
    8·1 answer
  • A projectile is launched with an initial speed of 40 mys from the foor of a tunnel whose height is 30 m. What angle of elevation
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!