Graphs of Motion · 7.2.1
Drawing speed-time graphs
Students plot speed against time for a given motion using tabulated or described data, selecting appropriate scales for both axes, and connect the points to form a line graph showing how an object's speed changes throughout its journey.
The official learning standard (7.2.1)
“Draw speed-time graphs.”
What it means
Students plot speed against time for a given motion using tabulated or described data, selecting appropriate scales for both axes, and connect the points to form a line graph showing how an object's speed changes throughout its journey.
How it is examined
Tested in Paper 2 as the opening part of a structured question, where students complete a table of speed values and plot a speed-time graph accurately, which is then used in later parts to find distance travelled or describe acceleration.
Worked example
A car accelerates uniformly from rest to 20 m/s in 5 seconds, then travels at a constant speed for the next 4 seconds. Draw the speed-time graph.
- From t = 0 s to t = 5 s, speed increases uniformly from 0 to 20 m/s: plot the straight line from (0, 0) to (5, 20).
- From t = 5 s to t = 9 s, speed stays constant at 20 m/s: plot the horizontal line from (5, 20) to (9, 20).
- Join (0, 0) to (5, 20) with a straight rising line, then draw (5, 20) to (9, 20) as a horizontal line.
Source:DSKP KSSM Mathematics Form 4 and 5 (Versi English)
Frequently asked questions
What is plotted on each axis of a speed-time graph?
Time is plotted on the horizontal axis and speed on the vertical axis, showing how speed changes as time progresses.
How is a speed-time graph different from a distance-time graph?
A speed-time graph shows how fast an object moves at each moment, while a distance-time graph shows the total distance covered up to each moment.
What does a straight rising line represent?
A straight rising line shows the speed increasing at a constant rate, meaning the object has uniform (constant) acceleration during that period.