5

1.5/2 points Previous AnswersOSColPhys2016 16.11.P.071,My NotesAsk Your Teacher(a) What is the intensity in W/m2 of a laser beam used to burn away cancerous tissue ...

Question

1.5/2 points Previous AnswersOSColPhys2016 16.11.P.071,My NotesAsk Your Teacher(a) What is the intensity in W/m2 of a laser beam used to burn away cancerous tissue that; when 92.0% absorbed puts 480 energy into circular spot 2.70 mm in diameter in 4.00 s? 2.1*10**8 Wlm?(b) Discuss how this intensity compares to the average intensity of sunlight (about 700 WIm2) and the implications it would have if laser beam entered your eye Note how your answer depends on the time duration of the exposure_ The

1.5/2 points Previous Answers OSColPhys2016 16.11.P.071, My Notes Ask Your Teacher (a) What is the intensity in W/m2 of a laser beam used to burn away cancerous tissue that; when 92.0% absorbed puts 480 energy into circular spot 2.70 mm in diameter in 4.00 s? 2.1*10**8 Wlm? (b) Discuss how this intensity compares to the average intensity of sunlight (about 700 WIm2) and the implications it would have if laser beam entered your eye Note how your answer depends on the time duration of the exposure_ The intensity is greater than the intensity of sunlight. That's it is used to burn cancerous tissue; laserII_sunlight-2.76*10**4 Score: out of Comment: Additional Materials Reading



Answers

a) What is the intensity of a laser beam used to burn away cancerous tissue that, when $90.0 \%$ absorbed, puts $500 \mathrm{J}$ of energy into a circular spot $2.00 \mathrm{mm}$ in diameter in 4.00 s? (b) Discuss how this intensity compares to the average intensity of sunlight (about) and the implications that would have if the laser beam entered your eye. Note how your answer depends on the time duration of the exposure.

So in part they were supposed to find the intensity off the laser beam. It is given that when 90% absorbed, it puts 500 Jude's off energy into it. So let's find the energy. First energy is 500 Jews divided by 0.9. So that the how much energy actually there is. This will give you 5 56 approximately keeping three significant digits. Then intensity is simply energy per unit area. Really, child. So energy is as we know 5 56 Then we are to divide this by pi. Really a square times the force seconds. So that's divided by four forced We get one 38.9 divided by high times. Now radius is one millimeter because diameter is two millimeters, then the radius should be one millimeter one times 10 power never to three times 10 power No time squared. That's it. So one thought here, divided by high, gives you 44 0.2 one times 10 power. So this is Gin Palace. Negative six of this we'll teach our positives. So this is intensity watch permits where this is the answer. Answer given on the numerator is not right. So now we can't find We can compare this as part pieces to the sun's intensity, which is 700. Watch for me to square. As you can see, the intensity here is 4.4 times 10 power seven, 4.4 times 10 power seven. So if you take a ratio off this, you'll find the answer is this will give you 6.6 times. Turn power four If you take the ratio of this intensity divided by this, this much stronger is intensity of compared to son straight. And if you hold it close to your eye off course you're born, you're I even in one seconds because in one seconds this will impart about 44.22 times 10 powers. Six words jewels for me, too square off energy. Of course, it depends on area off exposure as well. So if area exposure is small, no matter how small you make it, this is just hi. So this area is 3.14 times change our negative six such a small area. So off course, if you use this close to your eye, it can easily burn your eye

Every energies to find a power into type. Well, what is given 175 10 to the Power Ministry. Timing terrible is 102 seconds. So it is to be while 15 10 to the power My next tree. Junior. Mm. Mhm. Yeah. No second part. Mhm intensity at the point is defined as be upon mm for by our square power is 175 10 to the power. My history Yeah, Distance is 2.5 10 to 3. Power money. Six. So it is to me mhm 38 10 to the power minus six. What? Permata rescript Or it may be 3800 board or centimeters square. No sea park. Safe intensity for our I is given one and took 10 to the power. What person? 2 m square. So I upon ice if you can get 3800 upon 10 to the power minus two. So it is to be 3.8 10 to the power five fatter and sales

Already. Hello. We're going to dio problem 37 from chapter 32 of university physics with modern physics. So here we're dealing with a laser entering an eye and were given some information and asked to determine a few other parameters of the situation. So without further ado, let's just write down What the That's right down. What the question gives us were given that our laser has a wave link of 810 nanometers. The laser has a power equal to 250. Hello? Wants the diameter of the I. I'll put as big d with the sub. I is 510 micrometers, and the index of refraction in the eye is 1.34 Okay, so part A says at, um, if each pulse has 1.50 milliseconds, how long How much energy is delivered. So remember that power equals energy per unit time, so energy equals power. Times time. In this case, 250 million watts. Let's put everything in s unit so times 10 to the minus three watts and time is given in the problem as 1.50 milliseconds, 1.50 Millie is times 10 to the minus three seconds. Okay. And we multiply these two together in what we get is 3.75 times 10 to the minus four, Jules, or we can save 0.375 million jewels. Yeah, Okay, that's part a part B. Yeah, B is asking about the average pressure that is exerted on the retina that is fully absorbed by the circular spot. Right. So to find pressure, pressure equals intensity over the speed of light. Intensity is equal to power per unit area. Okay. And we have power 250 times 10 to the minus three watts. And the area we're talking about the area of the the retina in the eye, which is this is given as the diameter of course area is pi times the radius squared. We're gonna have pi times this diameter divided by two. And again we want to write out, Um, everything in s I units of times 10 to the minus 6 m over to. And that's squared. Right? So power here area of a circle is pi r squared. This is our diameter. So diameter over two is our radius okay. And if we plug that dark calculator, what we get for the intensity is 1.22 times 10 to the six. And that would be watts per meter squared. Okay, so now we're gonna take this value and plug it in over here. So we're going to get our intensity. We just found to be 1.22 times 10 to the six watts per meter squared over the speed of light, which is a known value. And then if we plug this into our calculator, we get 4.8 times 10 to the minus three. Pressure is Pascal's. Okay, Part C parties and index of refraction problem. So what are the wave length and frequency of the laser inside the vitreous humor of the eye. So our wavelength is given here, and this is outside of the eyes. So good way to do this is to draw a little picture where we have the air here and this is in the eye here. Now for the air. The index of refraction is 1.0 index of refraction. The I is given as one point 34 Now the frequency, um in the air is the same as frequent in the eye. Now, what changes is the speed at which the light is traveling in each of these media, so that also affects the wavelength. So we know that lambda one here. So I'll call this surface one in this surface to so lambda one equals 810 nanometers. The speed here is the speed of light. And then we're gonna have an s, uh, one the frequency here which will determine in a second. Same here, Lambda Two. We're gonna have to determine question marks for these, and feet two will have to determine, and f two equals f one way south to determine both of those. Okay, so for an air, we have the equation. Uh, f one equals the speed of light. Overland one three times. 10 to 8 meters per second over 810 times 10 to the minus 9 m. Plugged this in your calculator. And what you find is 3.70 running out of room times. 10 to the 14 hurts. Uh, so again, this is the same frequency that will find in, uh, in the eye as well. So now We found that. And the question asks for the frequency and the wavelength. Okay, so there's the frequency and you write it more explicitly. There s to equals. You see? Here, there we go. To erase this, I could just write it right here. Call 3.70 times. 10 to the 14 hurts. Okay? And then we also have the relationship that in one Lambda one equals and to Lambda, too. So determine the wavelength inside the eye, which we call medium number two. We're going to use this equation here. I am running out of room. Let's see. Can I take this down? Here we go. Okay. So lamb too equals in one. Lamda won over in two, which equals in one is 1.0 Lambda one is 810 nanometers and into is 1.34 Right. This is into this is in one. Yeah. Okay. Plug this into your calculator, and what you get is 604 nanometers. All right? And part D, once the maximum values of the electric and magnetic fields Well, for that, we're going to use intensity. And we had the equations. That intensity equals the max squared over to you not see So we can solve this for IMAX equals square root. Oh, I times two times You're not times See, um, you not is unknown. Constant four pi times 10 to the minus seven. That's Henry's per meter. Um, speed of light is a constant and we already found intensity above Um, it's here, so plug everything in and what we're gonna get. Come on. 0.22 times 10 to the six watts per meter Squared times two times four pi times 10 to the minus seven. Again, that's Henry's per meter. And I ran it room again. We're gonna have to multiply one more thing inside this square root That's three times 10 to the date meters per second, the speed of light. So all this is underneath this square root here. And when we plug all that into our calculator, we're gonna get 3.3 times 10 to the four Newtons per cool. Um, we also have the relationship that relates the electric field and magnetic field, and that is e over B equals C so we can solve for B. Well, say be Max equals E Max oversee. We just found MX to be 3.0 three times 10 to 4 Newtons per Coolum over three times 10 to 8 m per second. Like this into the calculator. And what we get for the maximum magnetic field is 1.1 times 10 to the minus four. And that is Tesla's. All right, so that doesn't Thanks for watching.

All right. So for this problem, we have Ah, we were laser. Be so we already know that the laser, the laser beam has power Pequot. So there's the party. The power is that 2 50? Meaning what? And we also know the time for this These air been I mean for this post is uh ah. The total time is, uh, 1.5 made its second some part. I want to find out the energy for this pulse, so ah, we know that the energy equal power of times time. Right? So this gives the total energy of his pulse. So it's simply to 50 minute walked times 1.5. Wait a second. And this gives you Ah, 0.3 75. Many Joe's okay, in part B. Ah, we want to Ah, let me see. I want to find out the pressure induced by this. Ah, by this pulse. So you know, textbook, you can find the relation between the pressure of the laser beam and the intensity of the team. So the relation is Ah, the pressure. Radiation pressure equal. I oversee. So we're eyes. The intense intensity off this beam and C is the speed of light, so Ah, the intent. The intensity is defined as Ah, pee over s We're peas. The pressure, which is Ah, are peas. The power which is the one we found over here. And the S is the ah effected area off this Ah, of this laser beam. Because in this problem, we're considering situation that to the PM is ah fully absorbed by this Ah, normal surface. So this is the relation and the develop a c So Ah, we already know that the P is the 2 50 You know what? So the area is ah pi r squared right? Because it's it's just a circle circle area pi r squared and the rabbi sees sees the speed of light which is a constant. So the ari's not directly given the problem. But we already know the diameter d. So you can utilize the diamond her and ah, because our the radius equal d over too, right? So I can find out the radius of this beam and just plug in the number and they would see that it finally from the final result for this Ah ah, Radiation pressure is 4.8 minute Posca and in part, see Parsi. So suppose the laser beam enters into the human eye. We want to find out to the I basically want to find out that the frequency and the speed and the ah, the way blinds off the lights inside the eye. So Ah, we already know the reflection. The refraction factor inside the eye is that 1.34 So it'sjust idea case. So given this information ah, we also know that we've lands off this light Ihsaa So ah, this web lenses the weapons in the vacuum. Okay, so let's say this is a Lambda V V labels the vacuum So this is eight ton nano meters and ah, the speed of light. I mean, the speed of this beam is just the speed of light, which is a constant c. So let's see, this is the CVI, okay? It's also the labels, the vacuum, which is the three times 10 to the 10th meters per second and the frequency ihsaa Ah, the falcons. That can be calculated by this two variables. So the frequencies a c v three c v. Do you buy London? Be so just to use this to values and come in the character of this pregnancy. And the better you can tell us. Ah, three point 74 times turned to the 14th. I'm sorry. Just remove it. Times turned to the 14th hurts. Okay, so remember this our the situation in the vacuum because we want to find out the information. It's not the eye. So we need to do some more calculations because we're writing. Though the reflection factor is ah 1.34. So, basically, if the if the beam enter the eye the the frequency, we will remain unchanged. So their frequency if I simply equal to f b Okay, so it's the one that we found over here. 3.74 times 10 to the 14th herds. Remember? Ah ah for the electric magnetic wave. If it enters from one interior to the other material the frequency we're not We're not change. Okay, so you're the frequency would not change the change. Variables will be the wee plays and the speed. So basically the speed. Sorry. It's not to see the anymore. It's Ah. See, I see. I So the speed will be Ah, smaller. It actually a quote CV divide by in. Okay. Any of the reflection factor over here. And you consider that this study was Ah, Let me see. Two point. Ah, Hey, I think this I think I've done wrong calculation. Ah, but you can You can figure out this number. Okay, I think Michael Clayton, my number. He's wrong. But two CV here is simply three times 10 to the eighth and a is right here. And you could just use your calculator and do this one simple calculation. So this is the speed of light speed off lightly in there in the night. And the wavelengths Lunda I also it is also shrink tw so this becomes lumber V over, over in so long. Davey is right here. Ah, it's 802 millimeters and a CZ right here so we can find out this. Ah ah, We've lensing I which is the 604 Yeah, I believe this is right. Nine meters. So there's a parsi so far apart, D Let's see. Ah, we want to find out Ah, the maximum value for the electric field and magnetic field for this electromagnetic wave. So basically Ah, there's a relational textbook. Ah, and claiming that the intensity off the beam equal half Absolutely not. Times C times e. Max squid. Okay, so absolutely is the electric constant in the vacuum and the seas, the speed, the lights also in the vacuum. And e max is the one that we were gonna find out, which is the maximum, which is the magnitude of the Electra feud. So the intensity is the one that we have. Ah, we have figure out in the previous part. Let's see. Ah, intensity. Intensity. Is this one p over s. So this is the intensity. Okay, p or ass. So you can see that. Ah ah, All the variables are known in this equation. We already know intensity. We know this constant and we know this constant so we can figure out the value of the off this imax and you can just to solve this equation easily. And to see that imax equal Ah, 30.3 curable per meter. Okay. And the relation between the magnitude off the electric field and magnetic field in the electromagnetic wave. This Ah, you next equal. See, time's be Max. So C is also the speed of light in the vacuum and be Maxie's. The magnitude of the magnetic. A wave. So you came to IndyMac's equal. You next over seat. All right. And this gives you one No. One. Ah, micro Tessa. Okay, so, yeah, that's all.


Similar Solved Questions

5 answers
7.26 The lengths of the sardines received by cannery have mean 0f 4.64 inches standard deviation of 0.25 inch: If the distribution of these lengths can and with normal distribution. what percentage of all (hese approximated closely sardines are shorter than 4.00 inches: from 40 t0 80 inches long"'
7.26 The lengths of the sardines received by cannery have mean 0f 4.64 inches standard deviation of 0.25 inch: If the distribution of these lengths can and with normal distribution. what percentage of all (hese approximated closely sardines are shorter than 4.00 inches: from 40 t0 80 inches long&quo...
5 answers
Question (14 pts:) Give the IUPAC name for the following: Specify stereochemistry as appropriate :OMe
Question (14 pts:) Give the IUPAC name for the following: Specify stereochemistry as appropriate :OMe...
5 answers
Point) Consider the function f(x;y)4x) cos(y) . Suppose S is the surface z = f(x,y).(a) Find vector which is perpendicular to the level curve of f through the point (4,5) in the direction in which f decreases most rapidly: vector -50.4056088i-3.36405j(b) Suppose V = Si + Sj + ak is a vector in 3-space which is tangent to the surface S at the point P lying on the surface above (4,5). What is a?
point) Consider the function f(x;y) 4x) cos(y) . Suppose S is the surface z = f(x,y). (a) Find vector which is perpendicular to the level curve of f through the point (4,5) in the direction in which f decreases most rapidly: vector -50.4056088i-3.36405j (b) Suppose V = Si + Sj + ak is a vector in 3-...
5 answers
Suppose your college transeript shows the distribution of = grades;which grade would be equated with Given that all of these grades are In three-credit elasses plurality winner?H) BC)CD) D
Suppose your college transeript shows the distribution of = grades; which grade would be equated with Given that all of these grades are In three-credit elasses plurality winner? H) B C)C D) D...
5 answers
RAt | Cuoulns Fuu-TLeatingczhu 77"d57n ICHO Cotcu 0-0J60EGimgcno rdrmj cj4ADEclceto dord;LFetnTe Fu-buolulehendc DIAetTtettlentInuEuFAFM<GnitWendune" Heebtet atnelu B Anamngeuenetinrteeee { Aselab# Himcie)HalenaeAeeetSeCAFdetttAcotecmainingEeEEnesttFaeFaladOcautetIn Itla-itutzn iletntldaue 40enns itedulumateranaedttttdtamntuneetenMlereateabaalea
RAt | Cuoulns Fuu-T Leatingcz hu 77"d57n ICHO Cotcu 0-0J60EGimgcno rdrmj cj4ADEclceto dord; LFetnTe Fu-buolulehendc DIA etTtet tlent InuEu FAFM< GnitWendune" Heebtet atnelu B Anamngeuenetinrteeee { Aselab# Himcie) Halenae Aeeet Se CAFdettt Acotec maining EeEEnestt FaeFaladOcautet In It...
5 answers
The tank depicted below contains compressed air (at a pressure of 1178 mmHg) and mercury. There is thin tube starting at the base of the tank; which is open to the atmosphere_ What is the height, H (in m) ofthe mercury in the thin tube?Note: Figure not drawn to scale.Additional data:Density of mercury 13.60 Blcm' Barometric pressure, Patm 762 mmHg1178 mmHg air0.250 mmercuryA)0.416 m B) 0.666 m C) 0.166 m D) 1.940 m E} 1.430 m
The tank depicted below contains compressed air (at a pressure of 1178 mmHg) and mercury. There is thin tube starting at the base of the tank; which is open to the atmosphere_ What is the height, H (in m) ofthe mercury in the thin tube? Note: Figure not drawn to scale. Additional data: Density of me...
5 answers
An ideul gas (7 1.41 follows tbe cycle shown Figure The temneranin state is 2U) K Find the temperatures of the other three states of the cycle and the eflictency the cycle.Figure
An ideul gas (7 1.41 follows tbe cycle shown Figure The temneranin state is 2U) K Find the temperatures of the other three states of the cycle and the eflictency the cycle. Figure...
5 answers
Clasifique los conjuntos de puntos que satisfacen las siguientes relaciones:12 - 52/ =1b) 2 < Re(-2+3i+ (-2 - 5i) 2) < 6 33 < Re(5 + 5i + 2) d) M4-3i+2 > 0
Clasifique los conjuntos de puntos que satisfacen las siguientes relaciones: 12 - 52/ =1 b) 2 < Re(-2+3i+ (-2 - 5i) 2) < 6 33 < Re(5 + 5i + 2) d) M4-3i+2 > 0...
1 answers
In Exercises $29-32,$ (a) does the equation $A \mathbf{x}=0$ have a nontrivial solution and (b) does the equation $A \mathbf{x}=\mathbf{b}$ have at least one solution for every possible $\mathbf{b} ?$ $A$ is a $2 \times 4$ matrix with two pivot positions.
In Exercises $29-32,$ (a) does the equation $A \mathbf{x}=0$ have a nontrivial solution and (b) does the equation $A \mathbf{x}=\mathbf{b}$ have at least one solution for every possible $\mathbf{b} ?$ $A$ is a $2 \times 4$ matrix with two pivot positions....
1 answers
Use Part 1 of the Fundamental Theorem of Calculus to find the derivative of the function. $$y=\int_{1-3 x}^{1} \frac{u^{3}}{1+u^{2}} d u$$
Use Part 1 of the Fundamental Theorem of Calculus to find the derivative of the function. $$y=\int_{1-3 x}^{1} \frac{u^{3}}{1+u^{2}} d u$$...
4 answers
0-kg object moving at & m/s toward the cast suddenly collides with 15 kg object moving at 4 m/s toward the south Thc two cars stick together after the collision_ What is the speed of the cars after collision?2.2 ms5.6 ms8 ms4 DVsS
0-kg object moving at & m/s toward the cast suddenly collides with 15 kg object moving at 4 m/s toward the south Thc two cars stick together after the collision_ What is the speed of the cars after collision? 2.2 ms 5.6 ms 8 ms 4 DVs S...
5 answers
Point) Find all the eigenvalues (real and complex) of the matrix16 -2 ~9 M = 25 -3 -13 25 _6 -10The eigenvalues are(Enter youranswers as a comma separated list.)
point) Find all the eigenvalues (real and complex) of the matrix 16 -2 ~9 M = 25 -3 -13 25 _6 -10 The eigenvalues are (Enter your answers as a comma separated list.)...
5 answers
Person23456810Before:132135149133119121128132119110After:118137140130107116122124115103
Person 2 3 4 5 6 8 10 Before: 132 135 149 133 119 121 128 132 119 110 After: 118 137 140 130 107 116 122 124 115 103...

-- 0.023775--