Intensity is a measure of incoming power per unit area. If el is the intensity of the incoming energy within an illuminated region of area, A, then the total received power is given by: P = JA where I depends on the power of the radiating source, how it spreads and how far away it is from the illuminated region. shlight on a Wall Suppose that a flashlight beam spreads uniformly over a circular region as shown in the figure above. (a) If Pbulb is the radiated power, and r is the radius of the circle, which expression gives the intensity, , within the illuminated region? Pbulb 4tr² Pbulb Пре Pbulb 2πr (b) Which expression should you use to calculate the total incoming (received) power, Pin, over a square of side length, s, that is completely illuminated by the beam as shown in the above figure? O shel 0 Hrael Ο Ampel 8 You shine the 13.5-cm radius circular beam of a 70-W flashlight on a square sticky-note with side length 8.1-cm that is tacked to a nearby wall as shown in the figure above. (c) What is the total (average) power received across the circular beam. W (d) What is the total (average) power received across a sticky note? W (d) What is the intensity of the incident light on the sticky note? W/m² Area, A Intensity. I
Intensity is a measure of incoming power per unit area. If el is the intensity of the incoming energy within an illuminated region of area, A, then the total received power is given by: P = JA where I depends on the power of the radiating source, how it spreads and how far away it is from the illuminated region. shlight on a Wall Suppose that a flashlight beam spreads uniformly over a circular region as shown in the figure above. (a) If Pbulb is the radiated power, and r is the radius of the circle, which expression gives the intensity, , within the illuminated region? Pbulb 4tr² Pbulb Пре Pbulb 2πr (b) Which expression should you use to calculate the total incoming (received) power, Pin, over a square of side length, s, that is completely illuminated by the beam as shown in the above figure? O shel 0 Hrael Ο Ampel 8 You shine the 13.5-cm radius circular beam of a 70-W flashlight on a square sticky-note with side length 8.1-cm that is tacked to a nearby wall as shown in the figure above. (c) What is the total (average) power received across the circular beam. W (d) What is the total (average) power received across a sticky note? W (d) What is the intensity of the incident light on the sticky note? W/m² Area, A Intensity. I
Chapter9: Optics
Section: Chapter Questions
Problem 50Q
Related questions
Question
Transcribed Image Text:Intensity is a measure of incoming power per unit area.
If I is the intensity of the incoming energy within an
illuminated region of area, A, then the total received power is
given by:
P = JA
where I depends on the power of the radiating source, how it
spreads and how far away it is from the illuminated region.
lashlight on a Wall
Suppose that a flashlight beam spreads uniformly over a circular region as shown in the figure above.
(a) If P bulb is the radiated power, and r is the radius of the circle,
which expression gives the intensity, , within the illuminated region?
Pbulb
P bulb
4πr²
(b) Which expression should you use to calculate the total incoming (received) power, Pin, over a
square of side length, s, that is completely illuminated by the beam as shown in the above figure?
Os²el O² O 4πr²e
bulb
2ftr
You shine the 13.5-cm radius circular beam of a 70-W flashlight on a square sticky-note
with side length 8.1-cm that is tacked to a nearby wall as shown in the figure above.
(c) What is the total (average) power received across the circular beam.
W
(d) What is the total (average) power received across a sticky note?
W
(d) What is the intensity of the incident light on the sticky note?
W/m²
Area, A
Intensity. I
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 4 steps with 6 images
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Recommended textbooks for you
Physics for Scientists and Engineers, Technology …
Physics
ISBN:
9781305116399
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Physics for Scientists and Engineers, Technology …
Physics
ISBN:
9781305116399
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Glencoe Physics: Principles and Problems, Student…
Physics
ISBN:
9780078807213
Author:
Paul W. Zitzewitz
Publisher:
Glencoe/McGraw-Hill