GRAPHING MOTION Distance vs. Time

GRAPHING MOTION As with much of science, graphs are real life representations of how you display data! Plotting a distance vs. time graph can tell you a story about a journey.

GRAPHING MOTION Let's look at the axes: Time will ALWAYS be on the “X” axis. Distance will ALWAYS be on your “Y” axis.

GRAPHING MOTION Time = INDEPENDENT The further to the right, the longer time from the start.

GRAPHING MOTION Distance = DEPENDENT The higher up the graph we go, the further we are from the start.

GRAPHING MOTION If something is not moving, a horizontal line is drawn on a distance-time graph. Time is increasing to the right, but its distance does not change. This graph shows an object that is stationary.

GRAPHING MOTION If something is moving at a steady speed, it means we expect the same increase in distance in a given time. Time is increasing to the right, and distance is increasing steadily with time. Constant remains UNCHANGED! = steady speed; cruise control

GRAPHING MOTION This graph shows an object that moves at a steady, constant speed.

GRAPHING MOTION Both the lines below show that each object moved the same distance, but the steeper yellow line got there before the other one. What does this indicate?

GRAPHING MOTION A steeper slope indicates a larger distance moved in a given time. In other words, higher speed. This is shown in yellow.

GRAPHING MOTION For the first part of the journey shown by the graph below, the object moved at a steady (slow) speed.

GRAPHING MOTION Then the object suddenly increased its speed, covering a much larger distance in the same time. The speed increased in the second part of the journey.

GRAPHING MOTION The line below is curving upwards. This shows an increase in acceleration, since the slope is getting steeper over time.

GRAPHING MOTION In other words, in a given time, the distance the object moves is larger. It is accelerating.

GRAPHING MOTION Stopped? Moving at a quick constant speed? There are three parts to the journey shown here… Where is the graph showing motion that is: Stopped? Moving at a quick constant speed? Traveling at a slow constant speed? C B A

GRAPHING MOTION Distance vs. time graphs also indicate the position of the object. Stage 1 & Stage 2: object is moving away from the starting point Stage 3: object is moving back toward the starting point (it comes back to zero)

GRAPHING MOTION The steeper the line on a distance vs. time graph, the faster the object’s speed. A curved line indicates a change in speed (accelerating or decelerating).

GRAPHING MOTION Lines pointing up indicate moving away from the starting location. Lines pointing down indicate moving back towards the starting location.

DISTANCE-TIME GRAPHS Click to find out the answers! Work out the speed for each object shown in the graph! 1. Yellow line 30/10 = 3 m/s 2. Blue Line 20/10 = 2 m/s 3. Pink line 10/10 = 1 m/s A straight line shows an object moving at a constant speed! The steeper the line, the faster the object is moving!

STATIONARY OBJECTS! A flat, horizontal line shows a stationary object!

ACCELERATING OBJECTS Curved lines show if an object is accelerating or decelerating! The steeper the line gets the faster the object is moving!

GRAPH QUESTIONS! 1. What is the speed of the man during the first three seconds? 2. What is the man doing between 3 and 5 seconds? 3. Calculate the speed of the man between 5 and 7 seconds. 4. What is the total distance that he has moved? 5. Calculate the average speed for the whole journey. 1. 12/3 = 4 m/s 2. Stationary 3. 12/2 = 6 m/s 4. 24 m 5. 3.4 m/s Click for answers!

Analyze the graph in your SISN for motion Analyze the graph in your SISN for motion! Write in if the portion of the graph is increasing in speed and distance; distance/motion has stopped; or distance is decreasing heading back to original location.

GRAPHING MOTION Let’s see how much this makes sense to you… Complete the INDEPENDENT practice foldable on distance vs. time graphs.

GRAPHING MOTION To learn about speed vs. time graphs, visit this link: http://www.gcse.com/fm/stg.htm