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?

Physics for Scientists and Engineers, Technology Update (No access codes included)

9th Edition

ISBN:9781305116399

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter1: Physics And Measurement

Section: Chapter Questions

Problem 1.29P

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