1. Scale Models & The Solar System

2. What is a model in science?

3. Example: Models can help teach
What are some problems you see with the accuracy of this model?
Planets are the wrong size relative to each other
Distances are incorrect

4. Scale models
A copy of an object that is smaller (or larger) than the actual size of the object.

5. Scale Model Solar System
How do we make an accurate model of the solar system that is correct for the size of the planets and their distances?

6. We need to set up a scale (or ratio).
The blue bar tells us the map scale.
One blue bar : 1500 miles

7. But space is really, really big!
We will need a different scale

8. Let’s make the sun (800,000 miles in diameter) in our model the size of a volleyball (8 inches in diameter)

9. Making the scale model
Step 1: Set up our scale ratio Real distance : scale distance 100,000 miles : 1 inch or 3,600,000 miles : 1 yard
Distance?

10. __________ ________ = 3,600,000 miles 1 yard 36,000,000 miles
Step 2: Use the ratio to calculate the distances in our scale model by setting up equivalent fractions.
Actual distance in space : scale model distance
3,600,000 miles : 1 yard
__________
3,600,000 miles
________
1 yard =
36,000,000 miles
Actual distance from Sun to Mercury
x yards
Scale model distance from Sun to Mercury

11. __________ ________ = 3,600,000 miles 1 yard 36,000,000 miles
Step 3: Cross multiply to calculate the scale model distance.
Actual distance in space : scale model distance
__________
3,600,000 miles
________
1 yard =
1. multiply
3. equals
36,000,000 miles
Actual distance from Sun to Mercury
x yards
Scale model distance from Sun to Mercury
2. divide

12. __________ ________ = 10 3,600,000 miles 1 yard 36,000,000 miles
Step 4: Record scale model distance on your worksheet.
Actual distance in space : scale model distance
3,600,000 miles : 1 yard
__________
3,600,000 miles
________
1 yard = 10
36,000,000 miles
Actual distance from Sun to Mercury
___ yards
Scale model distance from Sun to Mercury
10 yds

13. Homework
36,000,000 miles 10

14. Homework
Calculate the scale model distances for each planet and record it on your sheet. (front page only)
Tomorrow-
Come in quickly and turn in your corrected current event
We will take your calculations and go outside to make our scale model solar system. (Please use the restroom BEFORE you come to science!)