Consider a bright star in our night sky. Assume its distance from Earth is 29.0 light-years (ly) and its power output is 4.00 x 104 w, about 100 times that of the Sun. One light-year is the distance traveled by light through a vacuum in one year. (a) Find the intensity of the starlight at the Earth. W/m2 (b) Find the power of the starlight the Earth intercepts. (The radius Earth is 6.38 x 10° m.) MW Need Help? Read It

Consider a bright star in our night sky. Assume its distance from Earth is 29.0 light-years (ly) and its power output is 4.00 x 104 w, about 100 times that of the Sun. One light-year is the distance traveled by light through a vacuum in one year. (a) Find the intensity of the starlight at the Earth. W/m2 (b) Find the power of the starlight the Earth intercepts. (The radius Earth is 6.38 x 10° m.) MW Need Help? Read It

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter24: Electromagnetic Waves

Section: Chapter Questions

Problem 26P

See similar textbooks

Similar questions

At what distance does a 100-W lightbulb produce the same intensity of light as a 75-W lightbulb produces 10 m away? (Assume both have the same efficiency for converting electrical energy in the circuit into emitted electromagnetic energy.)
(a) Calculate the range of wavelength for AM radio given its frequency range is 540 to 1600 kHz. (b) Do the same for the FM frequency range of 88.0 to 108 MHz.
What are the wavelengths of (a) X-rays of frequency 2.01017 Hz? (b) Yellow light of frequency 5.11014Hz ? (C) Gamma rays of frequency 1.01023Hz ?
(a) A jet airplane with a 75.0 m wingspan is flying at 280 m/s. What emf is induced between wing tips if the vertical component 01 the Earth’s field is 3.00105T ? (b) Is an emf of this magnitude likely to have any consequences? Explain.
A community plans to build a facility to convert solar radiation to electrical power. The community requires 1.00 MW of power, and the system to be installed has an efficiency of 30.0% (that is, 30.0% of the solar energy incident on the surface is converted to useful energy that can power the community). Assuming sunlight has a constant intensity of 1 000 W/m2, what must be the effective area of a perfectly absorbing surface used in such an installation?
Lunar astronauts placed a reflector on the Moon's Surface, off which a laser beam is periodically reflected. The distance to the Moon is calculated from the round-trip time. (a) To what accuracy in meters can the distance to the Moon be determined, if this time can be measured to 0.100 ns? (b) What percent accuracy is this, given the average distance to the Moon is 3.84108m ?
Suppose a spherical particle of mass m and radius R in space absorbs light of intensity I for time t. (a) How much work does the radiation pressure do to accelerate the particle (mm rest In the given tine It absorbs the light? (b) How much energy canted by the electromagnetic waves is absorbed by the particle over this time based on the radiant energy incident on the particle?
A 2.50-m-diameter university communications satellite dish receives TV signals that have a maximum electric field strength (for one channel) of 7.50 (V/m. (See Figure 24.28.) (a) What is the intensity of this wave? (b) What is the power received by the antenna? (c) If the orbiting satellite broadcasts uniformly over an area of 1.501013m2 (a large fraction of North America), how much power does it radiate? Figure 24.28 Satellite dishes receive TV signals sent from orbit. Although the signals are quite weak, the receiver can detect them by being tuned to resonate at their frequency.
Radio waves normally have their E and B fields in specific directions, whereas visible light usually has its E and B fields in random and rapidly changing directions that are perpendicular to each other and to the propagation direction. Can you explain why?
In what range of electromagnetic radiation are the electromagnetic waves emitted by power lines in a country that uses 50-Hz ac current?
Consider a bright star in our night sky. Assume its distance from Earth is 84.9 light-years (ly) and its power output is 4.00 × 1028 W, about 100 times that of the Sun. One light-year is the distance traveled by light through a vacuum in one year. (a) Find the intensity of the starlight at the Earth. W/m² (b) Find the power of the starlight the Earth intercepts. (The radius of Earth is 6.38 x 106 m.) MW
In a particular area of the country, electrical energy costs $0.18 per kilowatt-hour. (Round your answers, in dollars, to at least two decimal places.) (a) How much does it cost to operate an old-style incandescent 60.0-W light bulb continuously for 24 hours? $ (b) A modern LED light bulb that emits as much visible light as a 60.0-W incandescent only draws 8.50 W of power. How much does it cost to operate this bulb for 24 hours? $ (c) A particular electric oven requires a potential difference of 220 V and draws 20.0 A of current when operating. How much does it cost to operate the oven for 3.90 hours? $