Motion Graphs
Units What are the units of speed when: Distance is measured in metres and time in seconds Distance is measured in kilometres and time in hours Distance is measured in metres and time in minutes
Calculate Pairs of cameras spot your number plate, start a timer, and then spot your number plate again leaving a zone 800 m The speed cameras record that a car takes 350 seconds to move between them. Calculate the average speed of the car. Show your working. Give the unit. 2.28 m/s
Distance against time graphs
No movement? distance time
No movement distance time
Constant speed? distance time
Constant speed distance time
Constant speed distance The gradient of this graph gives the speed time
How would the graph look different for a faster constant speed? distance time
Constant speed fast distance time
How would the graph look different for a slower constant speed? fast How would the graph look different for a slower constant speed? distance time
Constant speed fast distance slow time
Getting faster? (accelerating) distance time
Getting faster distance time
Examples distance time
A car accelerating from stop and then hitting a wall distance time
A car accelerating from stop and then hitting a wall distance time
Speed against time graphs
No movement? speed time
No movement speed time
Constant speed? speed time
Constant speed speed time
How would the graph look different for a faster constant speed? time
Constant speed speed fast time
How would the graph look different for a slower constant speed? fast time
Constant speed speed fast slow time
Getting faster? (accelerating) speed time
Getting faster? (accelerating) speed Constant acceleration time
Getting faster? (accelerating) speed The area under the graph gives the distance travelled time
Example: speed time
A dog falling from a tall building (no air resistance) speed time
A dog falling from a tall building (no air resistance) speed time
A dog falling from a tall building (no air resistance) speed Area = height of building time
Be careful! speed time distance time
No movement speed time distance time
Constant speed speed time distance time Area = distance travelled
Constant acceleration speed time distance time Area = distance travelled
Too easy? I have a challenge for you! Can you watch the following video clip and use a stopwatch to determine how far the car travelled? I will provide you with a stopwatch and a table to fill in!
Activity Plot these results on a speed time graph, with time on the bottom axis (the x axis) and speed on the side axis (the y axis). Label the points where there is a change in motion A,B,C,D,E,F,H,I,J and K. Example: point A is at time 0 and speed 20.
Distance travelled in m Time in s Distance travelled in m 60 200 120 400 180 240 300 800 360 1200 420 480 1600 540 2000 600 2200 The table shows the data of a man’s journey from home to town. Use the data to accurately plot a distance/time graph of the journey. 1.The man catches a bus in to town. How long does he wait for the bus? 2.What is the average speed of the man walking? 3.How long would the journey have taken on foot?4.What could be happening between 360s-420s? 5.How far does he travel on the bus? 6.What is the average speed of the bus between stops?
Distance/Time graph of a man catching a bus in to town