RELATING GRAPHS TO EVENTS Independent Variable: The cause variable (the tested variable or input). Always labeled on the x axis of graph. Dependent Variable: The effect variable (output). Always labeled on the y axis of graph. Identify the Independent and Dependent Variables for the Following Situations: 1. A study was done to find if different tire treads affect the braking distance of a car. 2. The time it takes to run a mile depends on the person s running speed. 3. The height of bean plants depends on the amount of water they receive. 4. The higher the temperature of the air in the oven, the faster a cake will bake. 5. Lemon trees receiving the most water produced the most lemons. 6. An investigation found that more bushels of potatoes were produced when the soil was fertilized more. 7. Students measured the temperature of the water at different depths in Lake Skywalker and found that the temperature varied. 8. The amount of pollution produced by cars was measured for cars using gasoline containing different amounts of lead.
Question #1: What are the two variables in this situation? Question #2: Which variable is the independent variable? distance moving stationary moving moving time
This graph represents a person's hike on a mountainside A B C D What are the two variables? Time and Elevation Which is the independent variable? Time Is the person going up, down, or both? Up... elevation is increasing What could be happening in each segment? A: Walking quickly up the mountain B: Stopped for a break C: Walk less quickly D: Walked very slowly Pull for questions
Example 1 The graph represents which of the following: A car that is traveling at a constant speed. A car with decreasing speed. A car that is stopped. A car that is coming back. distance time
Example 2 The graph represents which of the following: A car that is traveling at a constant speed. A car with decreasing speed. A car that is stopped. A car that is coming back. distance time
Which story best represents the graph? Explain your thinking. Solution: C
Warm Up A Person's Height 1. Why does the graph not start at zero? HEIGHT 2. Why is the graph not a straight slanted line? 0 TIME 3. What does the flat part at the top represent?
Name Date Per Identify the Independent and Dependent Variables for the Following Situations: 1. 2. 3. 4. 5. Lemon trees receiving the most water produced the most lemons. 6. An investigation found that more bushels of potatoes were produced when the soil was fertilized more. 7. Students measured the temperature of the water at different depths in Lake Skywalker and found that the temperature varied. 8. The amount of pollution produced by cars was measured for cars using gasoline containing different amounts of lead. SOLUTIONS Relating Graphs to Events Worksheet #1 I: Amount of water D: Lemons Produced I: Amount of fertilizer D: Potatoes Produced I: Depth D: Temperature I: Amount of Lead in Gasoline D: Amount of Pollution Produced by the Car
5. 1. 010412a, P.I. 8.A.3 John left his home and walked 3 blocks to his school, as shown in the accompanying graph. What is one possible interpretation of the section of the graph from point B to point C? [A] John arrived at school and stayed throughout the day. [B] John reached the top of a hill and began walking on level ground. [C] John returned home to get his mathematics homework. [D] John waited before crossing a busy street. SOLUTIONS 6. The accompanying graph shows the amount of water left in Rover's water dish over a period of time. How long did Rover wait from the end of his first drink to the start of his second drink of water? [A] 10 sec [B] 30 sec [C] 75 sec [D] 60 sec 7. The accompanying graph shows Marie's distance from home (A) to work (F) at various times during her drive. a. Marie left her briefcase at home and had to return to get it. State which point represents when she turned back around to go home and explain how you arrived at that conclusion. b. Marie also had to wait at the railroad tracks for a train to pass. How long did she wait? a. She turned back around to go home at point B because from B to C her distance from home goes back to 0 miles. b. Marie waited 5 minutes for the train to pass.