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Ch 31: Electromagnetic Fields and Waves
Knight Calc - Physics for Scientists and Engineers 5th Edition
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Knight Calc 5th EditionCh 31: Electromagnetic Fields and Waves문제 50a
31장, 문제 50a

The intensity of sunlight reaching the earth is 1360 W/m2. Assuming all the sunlight is absorbed, what is the radiation-pressure force on the earth? Give your answer in newtons.

검증된 단계별 안내
1
Understand the concept: Radiation pressure is the pressure exerted by electromagnetic radiation on a surface. If all the sunlight is absorbed, the radiation pressure can be calculated using the formula: P = Ic, where I is the intensity of sunlight and c is the speed of light in a vacuum.
Calculate the radiation pressure: Substitute the given intensity of sunlight, I = 1360 W/m^2, and the speed of light, c = 3.00 × 10^8 m/s, into the formula for radiation pressure.
Determine the force due to radiation pressure: The force exerted by radiation pressure on the Earth can be calculated using the formula: F = P × A, where A is the cross-sectional area of the Earth that intercepts sunlight. The cross-sectional area of the Earth is given by A = πr^2, where r is the radius of the Earth.
Substitute the radius of the Earth: Use the Earth's radius, r = 6.37 × 10^6 m, to calculate the cross-sectional area A. Then, substitute this value and the previously calculated radiation pressure P into the formula for force.
Simplify the expression: Perform the necessary calculations to simplify the expression for the force F. This will give you the radiation-pressure force on the Earth in newtons.

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Radiation Pressure

Radiation pressure is the force exerted by electromagnetic radiation on a surface. It arises from the momentum carried by photons, which can impart momentum when they are absorbed or reflected. The pressure can be calculated using the formula P = I/c, where P is the radiation pressure, I is the intensity of the radiation, and c is the speed of light in a vacuum.
추천 영상:
가이드 코스
07:51
Radiation Pressure

Intensity of Radiation

Intensity is defined as the power per unit area carried by a wave, in this case, sunlight. It is measured in watts per square meter (W/m²) and represents how much energy is delivered to a surface over a specific time. The intensity of sunlight reaching the Earth is approximately 1360 W/m², which is crucial for calculating the radiation pressure.
추천 영상:
가이드 코스
07:51
Radiation Pressure

Force Calculation

Force can be calculated using the relationship between pressure and area. The total force exerted by radiation pressure on an object can be found using the formula F = P × A, where F is the force, P is the radiation pressure, and A is the area over which the pressure is applied. In this context, the area would be the cross-sectional area of the Earth exposed to sunlight.
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가이드 코스
06:09
Work Done by a Constant Force
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