1. 2.1 Using Scientific Models to Predict Speed
How can you predict the speed of the car at any point on the ramp?

2. Key Points Models: Graphs: Difference types Using them Making them
Reading them

3. Why models? Answer big questions by breaking them into smaller pieces
Save money
Avoid mistakes
Understand nature

4. Scientific Models Show how variables relate to one another
4 different types:
Mental
Physical
Conceptual
Graphical

5. Mental Models Visualize / imagine what you want to happen
Use these to make hypotheses
Example:
Before kicking a ball to make a goal, you picture the kick and can make adjustments before you even kick it!

6. Physical Models
Touchable models that we can manipulate and make measurements from
AKA scale models
Example:
Building a small model of a bridge to see how it reacts to things such as wind and weight before spending a ton of money making a real bridge

7. Conceptual Models Describe how something works Descriptive!
Big picture
Example:
Copernicus described how the Earth revolves around the Sun
Galileo, Kepler, and Newton added to this model

8. Graphical Model
Uses a graph to show the relationship between variables
AKA mathematical model
Terms:
Dependent variable: depends (or changes because of the other variable
On y-axis (vertical one)
Independent variable: variable we are free to set as we want
On x-axis (horizontal one)
Add parenthesis after changes

9. Making a Graph Decide what to put on x and y
Usually says in your lab
Make a scale for each axis
Each square should be the same value
Possible method:
Count number of squares on that axis
Divide your largest value by the number of squares from above
Round to the nearest whole number

10. Making a Graph Plot your points Do NOT connect the dots!
Start with the x value
Slide up vertically until you hit the y number
Make your point
Do NOT connect the dots!
Draw a best-fit curve or line (I’ll tell you which one)
Make a title for your graph
It should relate to your graph

11. Making a Prediction After making your curve:
Find your starting value on your x-axis
Must be a place that is one your graph, but you didn’t measure
Draw a vertical line until you hit your curve
Draw a horizontal line until you hit the y-axis
Use the scale to record your predicted speed
Change one to on underneath number 1.

12. Relationships
Four types:
Strong
Weak
Inverse
none

13. Lab Reminders Section 1: Section 2: Circle the formula!
Choose 8 locations on the ramp
Locations should be at regular intervals
Car always travels the same distance!
Section 2:
For your graph:
Position on the x-axis
Speed on the y-axis

14. Lab Reminders Section 4:
Subtract the large number from the small number
It doesn’t have to be predicted - actual