Inverse Square Law

Light Intensity: As one gets further from a light source, the intensity of light....

• Increases

• Decreases

• Gets brighter

• Gets more luminous

A student stands 10 feet away from a light bulb. The student walks toward the light bulb to a 5 feet distance. Which is true? Intensity = 1 / d²

• The bulb appears 2x's brighter

• The bulb appears 4x's brighter

• The bulb appears 5x's brighter

• The bulb appears 25x's brighter

Based on the picture...what is the RATE of change of light intensity as one moves FURTHER from the light source?

• Light intensity INCREASES at an inverse square

• Light intensity INCREASES as a direct relationship

• Light intensity DECREASES at an inverse square

• Light intensity INCREASES as a direct relationship

SOLVE: A light bulb has an intensity of 50 watts at a distance of 1 meter. What is the intensity of the light at 5 meters? Intensity = 1 / d²

• 1 watt

• 2 watts

• 5 watts

• 10 watts

As one approaches (gets closer) to a light bulb, the brightness of the bulb....

• Increases (brighter)

• Decreases

• Stays the same

• Changes in some unknown way

At a distance of 1m, the intensity of light is spread over a 1m x 1m area. What is the area of light spread out at distance 2m?

• 1 m²

• 2 m²

• 4 m²

• 8 m²

SOLVE: An iPhone light shines at 40 watts from 6 meters away. What is the intensity of light at 2 meters away?

• 120 watts

• 160 watts

• 360 watts

• 720 watts

SOLVE: An iPhone light shines at 40 watts from 6 meters away. What is the intensity of light at 12 meters away?

• 80 watts

• 20 watts

• 15 watts

• 10 watts

Tags

NGSS.MS-PS4-1

• Earth, Mars, Venus

• Earth, Venus, Mars

• Venus, Mars, Earth

• Venus, Earth, Mars

Tags

NGSS.MS-PS2-4

Which of the following graphs best represents the gravitational force between two point masses as a function of the distance between the masses?

• 
• 
• 
• 

Tags

NGSS.HS-PS2-4