A regular LED light bulb continuously emits 10.0 W of light uniformly in all directions. A man stands so that his eyes are 5.00 m away from this light bulb and he is looking directly at the light bulb. There are no other sources of light in this room. (a) What is the irradiance of this light in W/m2 just before entering this man's eyes? (b) If each pupil of this man is contracted to a radius of 2.00 mm, what is the total power in W of the light entering each eye? (c) A human receives 3300 J of usable energy after eating one blueberry. How long would this man have to stare at this light bulb in order to take into his eyes through the pupils the same amount of energy as eating a blueberry? Don't forget that he has two eyes! (Note that far more energy from the light is hitting his skin, but that is not what we care about here.)
A regular LED light bulb continuously emits 10.0 W of light uniformly in all directions. A man stands so that his eyes are 5.00 m away from this light bulb and he is looking directly at the light bulb. There are no other sources of light in this room. (a) What is the irradiance of this light in W/m2 just before entering this man's eyes? (b) If each pupil of this man is contracted to a radius of 2.00 mm, what is the total power in W of the light entering each eye? (c) A human receives 3300 J of usable energy after eating one blueberry. How long would this man have to stare at this light bulb in order to take into his eyes through the pupils the same amount of energy as eating a blueberry? Don't forget that he has two eyes! (Note that far more energy from the light is hitting his skin, but that is not what we care about here.)
Principles of Physics: A Calculus-Based Text
5th Edition
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Raymond A. Serway, John W. Jewett
Chapter24: Electromagnetic Waves
Section: Chapter Questions
Problem 53P
Related questions
Concept explainers
Compton effect
The incoming photons' energy must be in the range of an X-ray frequency to generate the Compton effect. The electron does not lose enough energy that reduces the wavelength of scattered photons towards the visible spectrum. As a result, with visible lights, the Compton effect is missing.
Recoil Velocity
The amount of backward thrust or force experienced by a person when he/she shoots a gun in the forward direction is called recoil velocity. This phenomenon always follows the law of conservation of linear momentum.
Question
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 5 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
Principles of Physics: A Calculus-Based Text
Physics
ISBN:
9781133104261
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:
9781133104261
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning