Course: Combined Science + Separate Physics | Tier: Foundation + Higher | Linked: Motion graphs notes · Speed questions
✏️ You need: 3 sheets of A4 graph paper (one per task – stick them into your book afterwards), a sharp pencil, a ruler and a calculator. Draw every graph before opening any answers.
📌 KEY DEFINITIONS – learn them word for word
Speed = distance ÷ time. Unit: m/s.
Sloping straight line = moving at a constant speed. Steeper line = faster. Flat line = stopped (not moving).
The steepness (gradient) of a distance–time graph = the speed.
How to draw the graph
- Turn a sheet of A4 graph paper landscape (long side along the bottom). The big squares are 1 cm.
- Draw the axes with a ruler, about 2 cm in from the bottom and left edges. Time (s) goes along the bottom. Distance (m) goes up the side.
- Use the 📏 scale given for each task. Only number the big lines.
- Plot the points from the table as small crosses.
- Join the crosses with straight lines using a ruler.
- Label the three parts A, B and C.
🔍 See examples of distance–time graphs
🧮 The rule you need
Speed = distance ÷ time
For each part of the graph:
Step 1: How far did they go in that part? (bigger distance − smaller distance)
Step 2: How long did that part take? (bigger time − smaller time)
Step 3: Divide the distance by the time.
Task 1: The walk to the park 🚶
Sam walks 200 m to the shop in 100 seconds. He spends 100 seconds in the shop. Then he is late, so he runs the last 200 m to the park in 50 seconds.
| Time (s) | 0 | 100 | 200 | 250 |
| Distance (m) | 0 | 200 | 200 | 400 |
📏 Scale for Task 1:
Time (along the bottom): 1 big square = 20 s. Number the big lines 0, 20, 40, 60 … up to 260.
Distance (up the side): 2 big squares = 100 m. Number every second big line 0, 100, 200, 300, 400.
Tip: 250 s is halfway between the 240 and 260 lines.
Q1 Work out Sam’s speed in part A.
Show answer
Distance = 200 m. Time = 100 s.
Speed = 200 ÷ 100 = 2 m/s
Q2 What is Sam doing in part B? How can you tell from the graph?
Show answer
He is stopped (in the shop). The line is flat – his distance is not changing. His speed is 0 m/s.
Q3 Work out Sam’s speed in part C.
Show answer
Distance = 400 − 200 = 200 m. Time = 250 − 200 = 50 s.
Speed = 200 ÷ 50 = 4 m/s
Q4 Which line is steeper, A or C? What does this tell you?
Show answer
C is steeper, so Sam was going faster in part C (he was running).
Task 2: The car and the traffic lights 🚗
A car drives 100 m in 10 seconds. It waits at red traffic lights for 20 seconds. When the lights go green, it drives 300 m in 20 seconds.
| Time (s) | 0 | 10 | 30 | 50 |
| Distance (m) | 0 | 100 | 100 | 400 |
📏 Scale for Task 2:
Time (along the bottom): 2 big squares = 5 s. Number every second big line 0, 5, 10, 15 … up to 50. The axis is 20 cm long.
Distance (up the side): 2 big squares = 100 m. Number every second big line 0, 100, 200, 300, 400.
Q5 Work out the speed of the car before the traffic lights.
Show answer
Speed = 100 ÷ 10 = 10 m/s
Q6 For how long is the car stopped at the lights?
Show answer
From 10 s to 30 s, so 20 s (the flat part of the line).
Q7 Work out the speed of the car after the lights.
Show answer
Distance = 400 − 100 = 300 m. Time = 50 − 30 = 20 s.
Speed = 300 ÷ 20 = 15 m/s
Task 3: The jogger 🏃
A jogger runs 300 m in 100 seconds. She stops for 20 seconds to tie her shoelace. She is tired, so she walks the last 150 m in 100 seconds.
Make your own table this time: fill in the distances at 0 s, 100 s, 120 s and 220 s.
Check your table
Time (s): 0, 100, 120, 220 · Distance (m): 0, 300, 300, 450
📏 Scale for Task 3:
Time (along the bottom): 1 big square = 20 s. Number the big lines 0, 20, 40 … up to 240.
Distance (up the side): 2 big squares = 100 m. Number every second big line 0, 100, 200 … up to 500.
Tip: 450 m is halfway between the 400 and 500 lines.
Q8 Work out her running speed and her walking speed.
Show answer
Running: 300 ÷ 100 = 3 m/s
Walking: 150 ÷ 100 = 1.5 m/s
Q9 Describe her journey in words. Use the words constant speed, stopped, faster and slower.
Show answer
0 to 100 s: she runs at a constant speed of 3 m/s (steep line).
100 to 120 s: she is stopped (flat line).
120 to 220 s: she walks at a slower constant speed of 1.5 m/s (less steep line).
⚠️ Where students lose marks
- On a distance–time graph a flat line means stopped. On a speed–time graph a flat line means constant speed. Always read the label up the side first!
- Using the numbers from the whole journey instead of just one part. Work out how far and how long for that part only.
- Missing the unit: speed is m/s.
Next: Speed–time graph activity · Skydiver graph activity · Motion graphs notes
