12.10. We will learn in Chapter 14 that brightness of light called its intensity I is inversely proportional to the square of the distance r² from the light source. a. As r increases what happens to r² (does it increase or decrease)? What then happens to I (does it increase or decrease)? b. Write an equation that relates the two variables I, r² using an unknown constant k. c. The intensity from a light source is 50 Watts/meter2 when observed from 2 meters away. What is the value and units of the proportionality constant. What is the equation that relates the two variables I, r² using an unknown constant k. d. What intensity do you expect to measure at 10 meters away?

12.10. We will learn in Chapter 14 that brightness of light called its intensity I is inversely proportional to the square of the distance r² from the light source. a. As r increases what happens to r² (does it increase or decrease)? What then happens to I (does it increase or decrease)? b. Write an equation that relates the two variables I, r² using an unknown constant k. c. The intensity from a light source is 50 Watts/meter2 when observed from 2 meters away. What is the value and units of the proportionality constant. What is the equation that relates the two variables I, r² using an unknown constant k. d. What intensity do you expect to measure at 10 meters away?

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)...

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Electromagnetic Waves

Electromagnetic waves are waves that consist of magnetic field and electric field components perpendicular to each other. These field components are also perpendicular to the direction of propagation of the wave.

Question

12.10. We will learn in Chapter 14 that brightness of light called its intensity I is inversely
proportional to the square of the distance r² from the light source.
a. As r increases what happens to r² (does it increase or decrease)? What then happens to
I (does it increase or decrease)?
b. Write an equation that relates the two variables I, r² using an unknown constant k.
c. The intensity from a light source is 50 Watts/meter2 when observed from 2 meters away.
What is the value and units of the proportionality constant. What is the equation that relates
the two variables I, r² using an unknown constant k.
d. What intensity do you expect to measure at 10 meters away?

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