Shooting the Moon < 5 of 13 > Review | Constants Scientists can measure the distance to the moon with great accuracy by firing a laser pulse and then timing how. long it takes to see the reflection from mirrors left on the moon by Apollo astronauts 50 years ago. A laser beam may seem to be a perfectly straight line as it crosses a room, but any laser beam is actually spreading out as it travels because it has diffracted through a circular aperture as it leaves the laser. Correct The laser beam needs to diffract through an approximately 1-foot-diameter aperture as it leaves the laser in order for diffraction to be small enough to keep the beam diameter at the moon to no more than 2 km in diameter. These are not the size apertures for which we normally expect to see diffraction, but it's a real issue for light beams traveling these distances. The actual range-finding lasers use a shorter wavelength, which helps, but they also must allow for additional divergence as the laser beam passes through the atmosphere. So a 30 cm diameter is about what's needed even at a shorter wavelength. The laser uses a group of lenses of increasing size to accomplish this. Part C A laser used for lunar range-finding shoots a laser pulse with Eg 0.12 J of energy. The reflectors on the moon are 45 cm x 45 cm. If we assume that the laser beam energy is uniformly distributed - a rather poor assumption but adequate for making an estimate - how much laser-light energy hits the reflector? Express your answer in nanojoules. View Available Hint(s). Η ΑΣΦ ? E=120000000 nJ Submit Previous Answers X Incorrect; Try Again; 8 attempts remaining Provide Feedback Next >

Shooting the Moon < 5 of 13 > Review | Constants Scientists can measure the distance to the moon with great accuracy by firing a laser pulse and then timing how. long it takes to see the reflection from mirrors left on the moon by Apollo astronauts 50 years ago. A laser beam may seem to be a perfectly straight line as it crosses a room, but any laser beam is actually spreading out as it travels because it has diffracted through a circular aperture as it leaves the laser. Correct The laser beam needs to diffract through an approximately 1-foot-diameter aperture as it leaves the laser in order for diffraction to be small enough to keep the beam diameter at the moon to no more than 2 km in diameter. These are not the size apertures for which we normally expect to see diffraction, but it's a real issue for light beams traveling these distances. The actual range-finding lasers use a shorter wavelength, which helps, but they also must allow for additional divergence as the laser beam passes through the atmosphere. So a 30 cm diameter is about what's needed even at a shorter wavelength. The laser uses a group of lenses of increasing size to accomplish this. Part C A laser used for lunar range-finding shoots a laser pulse with Eg 0.12 J of energy. The reflectors on the moon are 45 cm x 45 cm. If we assume that the laser beam energy is uniformly distributed - a rather poor assumption but adequate for making an estimate - how much laser-light energy hits the reflector? Express your answer in nanojoules. View Available Hint(s). Η ΑΣΦ ? E=120000000 nJ Submit Previous Answers X Incorrect; Try Again; 8 attempts remaining Provide Feedback Next >

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The resolving power doubles. C. The resolving power is reduced to 1/2 of its original value. d. The resolving power is reduced to 1/4 of its original value. e The resolving power does not change unless the focal length changes. None of the above Find the angle of the refracted ray. n=2.41 23.6° 9=75.0⁰ a. b. 45.8° é [Q2] A ray of light is incident on a thick sheet of synthetic diamond (n=2.41) at an angle of 75.0°. nasina ng sine b = (2.41) Sin(75.0°) = n₂ 2.32=nb e C. 59.0° d. 75.0⁰ 98.6° None of the above f. =tan(2.33) =66/18 G en 5.00 m away. be 1.70 cm apa d=5
In the macroscopic world, you know that you can hear but cannot see around corners. Under what conditions does light bend around corners (i.e. diffract) ? Explain why sound diffracts easily around a classroom door.
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True or False? 1. The lens equation only applies when units are measured in cm. 2. Diffraction causes objects to bend away from the normal if n2>n1. 3. For a converging (convex) lens, m=1 only occurs when q = R. 4. Frequency is defined as the number of horizontal divisions on an oscilloscope. 5. For a sine wave, Vpp > Vp > Vrms. 6. Diffraction and refraction are two terms for the same effect.
Material MM C a- If the critical angle for total internal reflection is , what is n? b- For a light ray incident on a surface of MM from air, at incident angle = y, what is the reflection angle? And what is the refraction angle? c- For a light ray incident on the surface from MM, at angle to the normal, what is the angle of the out-going ray? Parameter values: 0, C (a) (b) (c) = 35.2 deg; y = 77.85 deg;
A beam of green light enters glass from air, at an angle of incidence = 39 degrees. The frequency of green light = 560 x 1012 Hz. Refractive index of 3 x 108 m/s. What will be its wavelength glass = 1.5. Speed of light in air inside the glass? Write your answer in terms of nanometers. You Answered 357 Correct Answer 804 margin of error +/- 3%
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II. Problem Solving. Show your step-by-step solutions. A transverse wave is propagating in a medium until it encounters another medium at an angle of incidence cqual to 30°. As a result, it refracts at an angle of 50° from the horizontal. What is its initial speed if its refracted wavclength and frequency are 0.02 meters and 5 Hz respectively?