Mr. Lambert Integrated Science 1A Trimester 1, 2014 Distance-time graphs Mr. Lambert Integrated Science 1A Trimester 1, 2014

Bell Ringer An athlete runs 200 meters in 50 seconds. What is her average speed? Mr. Lambert decides to drive to Chicago, which is 300 miles away. It takes him 6 hours to get there. What is his average speed?

Agenda Bell Ringer Learning Targets Class graph Lab activity Practice problems Exit Slip

Learning Targets On your Bell Ringer Sheet, write the following: We will interpret distance-time graphs

Distance-time graphs Distance (m) Time (s) 10 1.89 20 2.88 30 3.78 40 4.64 50 5.47 60 6.29 70 7.10 80 7.92 90 8.75 100 9.58 Usain Bolt – world record

Distance-time graphs What is the independent variable? Time x-axis What is the dependent variable? Distance Y-axis

Distance-time graphs

Table 1. Measuring Constant Velocity Distance-time graphs Table 1. Measuring Constant Velocity    Distance (m)  Time of Walker (s) First Second Third  0  5 4.55 2.78 1.46 10 9.07 5.49 3.19  15 15 8.62 4.58  20 18.4 11.57 6.1  25 23.94 15.06 7.87

Class distance-time graph

How does slope relate to speed? Slope (speed) = Rise (Distance) Run (Time)

What is this graph telling us?

Age

Student performance

Time increases to the right, but the distance does not change – object is at rest (not moving)

What does this tell us?

Age

Student Grades

Distance Same increase in distance in a given time – object moves at a constant speed

Dotted line – larger distance in given time (higher speed) Both lines are straight – constant speed

Age

Student grades

Downward sloping line – object returning to start Distance Downward sloping line – object returning to start

Simulation – the moving man http://phet.colorado.edu/en/simulation/moving-man

Distance-time graphs

Distance-time graphs

Draw the following scenario A man walks forward at a constant speed. Suddenly a dog starts to chase him and he begins to run. The man manages to outrun the dog and stops to take a break and catch his breath. The man then slowly walks back to his starting point.

Which of the graphs shows that one of runners started 10 yards further ahead of the other? Explain your answer.

In which of the following graphs above are both runners moving at the same speed? Explain your answer.

Exit Slip Describe the motion of the object from point A-B, B-C, and C-D. B C D A