Name:

# Inverse Square Law Practice 2

1. Complete this table:
 Distance from Light Source (meters) Light Intensity (candelas) 1 3 4 4.5 5 3200 800
2. The TV remote control uses infrared light to communicate with the TV. On the back of this sheet, draw a scale diagram showing how the light intensity varies with distance from the TV.
3. Why will making a telescope lens that gathers four times more light allow you to see stars only twice as far away?

4. Scientist Sheila wants to measure the response of cells to light. If she wants the light to be 10% of the current value, how far away must she move the light source? Would it help if I told you the light source is now 1cm from the cells.

5. Complete this table: AU = Astronomical Unit ≈ 93 million miles. G = strength of gravity at the Earth's surface.
 Distance from Planet (AU) Gravitational Intensity (G) 1 1.5 2 3 5 4 1 0.25
6. The Zorbon Intergalactic Empire uses gravity waves to communicate with their space craft. On the back of this sheet, draw a scale diagram showing how the gravity wave intensity varies with distance from the home planet of Zorbo.
7. Astronaut Bob Dobalina is monitoring asteroids in the Asteroid belt . He notices that as asteroids get closer to each other the gravitational attraction between the asteroids increases. Describe a rule for how the gravitational attraction will change if two asteroids get closer to one another. Give two examples of the rule in use. e.g. If the distance between two asteroids drops to 1/2 what it was, the gravitational attraction is now ___ times what it was.

8. Astronaut Doris Dobalina (Bob's sister) is also monitoring asteroids. She notices that gravitational attraction between the asteroids increases with the asteroid's mass. Describe a rule for how the gravitational attraction will change based on the asteroid's mass. Give two examples of the rule in use. e.g. If the mass of an asteroid doubles, the gravitational attraction is now ___ times what it was.