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Ch. 2 - Acute Angles and Right Triangles
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161, 9780135440780, 9780136881117, 9780135440827, 9780135924891당신이 사용하는 게 아니라요?교과서 변경
3장, 문제 2.3.83

(Modeling) Fish's View of the World The figure shows a fish's view of the world above the surface of the water. (Data from Walker, J., 'The Amateur Scientist,' Scientific American.) Suppose that a light ray comes from the horizon, enters the water, and strikes the fish's eye. Assume that this ray gives a value of 90° for angle θ₁ in the formula for Snell's law. (In a practical situation, this angle would probably be a little less than 90°.) The speed of light in water is about 2.254 x 10⁸ m per sec. Find angle θ₂ to the nearest tenth.

검증된 단계별 안내
1
Identify the given information: the angle of incidence \( \theta_1 = 90^\circ \) (the angle the light ray makes with the normal as it enters the water), and the speed of light in water \( v_2 = 2.254 \times 10^8 \) m/s. The speed of light in air \( v_1 \) is approximately \( 3.00 \times 10^8 \) m/s.
Recall Snell's Law, which relates the angles and speeds of light in two media: \[ \sin(\theta_1) \times v_1 = \sin(\theta_2) \times v_2 \]
Since \( \theta_1 = 90^\circ \), \( \sin(90^\circ) = 1 \), so the equation simplifies to: \[ v_1 = \sin(\theta_2) \times v_2 \]
Solve for \( \sin(\theta_2) \): \[ \sin(\theta_2) = \frac{v_1}{v_2} \]
Calculate \( \theta_2 \) by taking the inverse sine (arcsin) of the ratio: \[ \theta_2 = \arcsin \left( \frac{v_1}{v_2} \right) \] Round the result to the nearest tenth of a degree.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Snell's Law

Snell's Law describes how light bends when it passes between two media with different refractive indices. It states that n₁ sin(θ₁) = n₂ sin(θ₂), where n₁ and n₂ are the refractive indices and θ₁ and θ₂ are the angles of incidence and refraction. This law is essential for calculating the angle of refraction when light enters water from air.
추천 영상:
가이드 코스
4:35
Intro to Law of Cosines

Refractive Index and Speed of Light in Media

The refractive index (n) of a medium is the ratio of the speed of light in a vacuum to its speed in that medium. Since light travels slower in water than in air, water has a higher refractive index. Knowing the speed of light in water allows calculation of its refractive index, which is crucial for applying Snell's Law.

Critical Angle and Total Internal Reflection

The critical angle is the angle of incidence above which light cannot pass through the boundary and is instead totally internally reflected. When θ₁ approaches 90°, it relates to the critical angle scenario, affecting how light rays from the horizon enter the water. Understanding this helps interpret the physical meaning of the given angle in the problem.
추천 영상:
5:30
Trig Values in Quadrants II, III, & IV
관련 실천
교과서 질문

Find a value of θ in the interval [0°, 90°) that satisfies each statement. Give answers in decimal degrees to six decimal places. See Example 2.

cos θ = 0.85536428

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교과서 질문

CONCEPT PREVIEW Match each trigonometric function value or angle in Column I with its appropriate approximation in Column II.


Column I: 1.

cot⁻¹ 30

Column II:

A. 88.09084757°

B. 63.25631605°

C. 1.909152433°

D. 17.45760312°

E. 0.2867453858

F. 1.962610506

G. 14.47751219°

H. 1.015426612

I. 1.051462224

J. 0.9925461516

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교과서 질문

Concept Check The two methods of expressing bearing can be interpreted using a rectangular coordinate system. Suppose that an observer for a radar station is located at the origin of a coordinate system. Find the bearing of an airplane located at each point. Express the bearing using both methods. (0, -2)

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교과서 질문

Solve each problem. See Examples 3 and 4. Height of an Antenna A scanner antenna is on top of the center of a house. The angle of elevation from a point 28.0 m from the center of the house to the top of the antenna is 27°10', and the angle of elevation to the bottom of the antenna is 18°10'. Find the height of the antenna.

861
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교과서 질문

Find two angles in the interval [0°, 360°) that satisfy each of the following. Round answers to the nearest degree. cos θ = 0.10452846

608
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교과서 질문

Use a calculator to approximate the value of each expression. Give answers to six decimal places. tan 11.7689°

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