The Old North Church: During the American Revolution, Paul Revere instructed a friend to signal him of the approach of the British army. His friend was to use lanterns in the North Church in Boston, Massachusetts: "one if by land, and two if by sea." Paul Revere would watch for the signal from Charlestown, across the river. How far apart did the lanterns have to be placed in order for Paul Revere to reliably distinguish one lantern from two? Suppose the Old North Church in Boston was about 2.1 km from Paul Revere's spot in Charlestown. Assume the diameter of Paul Revere's pupil was about 4.9 mm. You may treat the lanterns as point sources. Assume the effective wavelength of light from each lantern was approximately 630 nm, and the total power output of a lantern was 0.3 W.

The Old North Church: During the American Revolution, Paul Revere instructed a friend to signal him of the approach of the British army. His friend was to use lanterns in the North Church in Boston, Massachusetts: "one if by land, and two if by sea." Paul Revere would watch for the signal from Charlestown, across the river. How far apart did the lanterns have to be placed in order for Paul Revere to reliably distinguish one lantern from two? Suppose the Old North Church in Boston was about 2.1 km from Paul Revere's spot in Charlestown. Assume the diameter of Paul Revere's pupil was about 4.9 mm. You may treat the lanterns as point sources. Assume the effective wavelength of light from each lantern was approximately 630 nm, and the total power output of a lantern was 0.3 W.

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

See similar textbooks

Similar questions

Unpolarized light having intensity lo falls upon a sequence of three polarizers with the transmission axes at angles of 0°, 30°, and 75° with respect to the vertical respectively. Find the intensities after the beam emerges from each of the three polarizers. ーと lo 1; = ? 12= ? Ipinai = ? unpolarized O = 0° O = 30° O = 75°
The physicist Albert Michelson invented two famous pieces of experimental equipment. The was able to measure the speed of light while the could measure the wavelength of a single coloured coherent light source. O Rotating Mirror Experiment, Raman Spectrometer O Michelson Interferometer, Rotating Mirror Experiment O Raman Spectrometer, Rotating Mirror Experiment O Rotating Mirror Experiment, Michelson Interferometer
3. A beam of polarised light (vertical linear polarisation) is perpendicular incident on an ideal linear polariser. If its transmission axis makes an angle of 60 degree with the vertical , what intensity of light will be transmitted by the polarizer?
What is the difference between the value obtained using E= I/(d2) and E = (# ∙ n ∙ LM ∙ CU ∙ LLF)/A. When will we use one or the other? E=illuminance I=luminous intensity d= distance from light source toobject Lumen Output (LM) Light loss factor (LLF) Number of lamps in luminaires (n) Number of luminaires (#) Coefficient of utilization (CU) Area (A)
Do you think Huygens’ principle is important? Why? What type of experimental evidence indicates that light is a wave? Give an example of a wave characteristic of light that is easily observed outside the laboratory.
** 12. Wilmington, North Carolina, is 5024 km due east of Santa Barbara, California. High- speed communication between the two cities can be accomplished by use of satellite commu- nication to a satellite that is a distance of 3456 km away from each city or by direct fiber optic cable between the two cities in a fiber whose index of refraction is n = 1.62. How long would it take each signal to go from Santa Barbara to Wilmington? 3456 km 5024 km- Santa Barbara Wilmington
B7
5) In the year 1178, five monks at Canterbury Cathedral in England observed what appeared to be an asteroid colliding with the moon, causing a red glow in and around it. It is hypothesized that this event created the crater Giordano Bruno, which is right on the edge of the area we can usually see from Earth. a) How long after the asteroid hit the Moon, which is 3.84 × 105 km away, would the light first arrive on Earth in seconds?
Light passes through two different polarizers. The first is aligned vertically, while the second is aligned horizontally. How much light makes it through the two polarizers?
If Unpolarized light is incident from the left on three polarizers as shown in Fig. below, in which case(s) will NOT some light get through? Cases 1 and 2. Case 2 and 3. Case 1 and 3. O Case 1 only. O Case 3 only. HII 0
Can you make sure you have the right answer???
2 Take a vertical polarizer and look through it. Take a second polarizer rotated at 90° (so it becomes a horizontal polarizer) and put it in front of the first one. How much light coming out of the vertical polarizer makes it through the horizontal one? Answer: 3 Are horizontal and vertical polarizations are mutually exclusive? Answer:.