how light spreads out
DESCRIPTION
How Light Spreads Out. Lesson 4. What’s the deal?. The Sun is one medium size star. The Andromeda Galaxy is a cluster of hundreds of billions of stars*, most are larger than the Sun. Why is the Sun so incredibly much brighter than the whole Andromeda Galaxy? - PowerPoint PPT PresentationTRANSCRIPT
How Light Spreads OutLesson 4
What’s the deal?The Sun is one
medium size star.The Andromeda
Galaxy is a cluster of hundreds of billions of stars*, most are larger than the Sun.
Why is the Sun so incredibly much brighter than the whole Andromeda Galaxy?
*710,000,000,000 solar masses according to Wikipedia.
What should I put in my data table?
Ideal Data (Don’t Change Yours)
Distance from Light
Source
Area of Illumination
(Lit Area)10 cm 1 cm2
20 cm 4 cm2
30 cm 9 cm2
40 cm 16 cm2
50 cm 25 cm2
What kind of graph should we use?
Exponential Relationship
10 20 30 40 50 60 70 800
10
20
30
40
50
60
70
Distance from Light Source vs. Area of Illumination
Area of Illumination
Distance from the Light Source
Area
of I
llum
inat
ion
Formula:Area of Illumination = (Distance to Light
Source/10)2
y=(x/10)2 Where y=Area of Illumination and x=Distance to the Light Source