🔀 Do Now — Unscramble the Words
📋 Instructions
These are all key words from Motion. Unscramble each word and type your answer in the box. When you're done, click Show Answers.
📚 Key Vocabulary
💡 How to use these cards
Click each card to reveal the definition. Try to say the definition in your head before you click — this is retrieval practice!
📊 Scalar vs Vector
🎯 Key Distinction
Some quantities only have a size (magnitude). Others have both a size AND a direction.
| Type | Definition | Examples |
|---|---|---|
| Scalar | Has magnitude (size) only | Speed, Distance, Mass, Temperature |
| Vector | Has magnitude AND direction | Velocity, Displacement, Force, Acceleration |
🚀 Speed, Distance & Time
⭐ The equation — learn this!
Speed = Distance ÷ Time | v = s ÷ t
Speed in m/s · Distance in metres (m) · Time in seconds (s)
Formula Triangle
Cover the quantity you want to find with your finger — the triangle shows you what to do with the other two.
The Three Rearrangements
- Speed: v = s ÷ t
- Distance: s = v × t
- Time: t = s ÷ v
🚶 Typical Speeds
You need to know roughly how fast these things move.
| Activity / Object | Speed (m/s) | Speed (km/h) |
|---|---|---|
| 👣 Walking | ≈ 1.5 m/s | ≈ 5 km/h |
| 🏃 Running | ≈ 3 m/s | ≈ 11 km/h |
| 🚲 Cycling | ≈ 6 m/s | ≈ 22 km/h |
| 🚗 Car (urban) | ≈ 13 m/s | ≈ 50 km/h |
| 🚗 Car (motorway) | ≈ 30 m/s | ≈ 110 km/h |
| ✈️ Aeroplane | ≈ 250 m/s | ≈ 900 km/h |
| 🔊 Speed of Sound | 330 m/s | ≈ 1200 km/h |
✏️ Worked Examples
📖 Example 1 — Finding Speed
Will walks 200 metres in 40 seconds. What is his speed?
📖 Example 2 — Finding Distance
Aaron travels at 50 m/s for 20 s. How far does he go?
📝 Practice Questions — Speed
💡 Scaffold
Use the formula triangle! Write down what you know first, then substitute. Always include the unit (m/s).
📈 Distance-Time Graphs — Key Ideas
🔑 The gradient = the speed
On a distance-time graph, the steeper the line, the faster the object is moving. Gradient = rise ÷ run = change in distance ÷ change in time = speed.
How to calculate speed from the graph
📖 Method: Gradient = Rise ÷ Run
📊 Graph 1 — Read the Graph
📊 Graph 2 — Who Is Fastest?
This graph shows four different people's journeys. Use the gradients to answer the questions.
📊 Graph 3 — Velocity from a Graph
💡 Note
Velocity is speed with a direction. On a distance-time graph, a downward slope means the object is travelling back towards the start — this gives a negative velocity.
📊 Graph 4 — More Practice
✏️ Drawing Task — Christina's Journey
📋 Task
On paper or in your notebook, draw a distance-time graph for Christina's journey:
- Walks 50 m in 20 seconds
- Stands still for 10 seconds
- Runs 100 m further in 30 seconds
- Stands still again for 20 seconds
- Walks all the way back to the start (150 m) in 50 seconds
💡 Hint: Your time axis goes to 130 s. Your distance axis needs to go to at least 150 m.
The graph goes up steeply (fast walk), flat (stationary), up steeply again (run), flat (standing), then comes back down to zero.
⚡ Acceleration
⭐ The equation — learn this!
Acceleration = Change in Velocity ÷ Time | a = (v − u) ÷ t
a in m/s² · v = final velocity (m/s) · u = initial velocity (m/s) · t = time (s)
Formula Triangle
The top section is the change in velocity (v − u).
💡 What is deceleration?
Deceleration is negative acceleration — the object is slowing down. You get a negative value for a when v is smaller than u. Just write the magnitude and say "deceleration".
✏️ Worked Examples — Acceleration
📖 Example 1 — Finding Acceleration
A cyclist accelerates from 0 to 10 m/s in 5 seconds. What is her acceleration?
📖 Example 2 — Finding Final Velocity
A ball accelerates at 10 m/s² for 5 seconds from rest. How fast will it be going?
📝 Practice Questions — Acceleration
💡 Scaffold
Always write u (start speed) and v (end speed) first. Calculate (v − u) before dividing by time.
📈 Velocity-Time Graphs — Key Ideas
🔑 Area under a V-T graph = Distance travelled
To find the total distance, calculate the area of each shape under the line:
- Rectangle: Area = base × height (= time × velocity)
- Triangle: Area = ½ × base × height
- Trapezium: Area = ½ × (a + b) × height
Add all the shapes together to get the total distance!
How to find acceleration from a V-T graph
📖 Method: Gradient = Change in Velocity ÷ Time
📊 V-T Graph 1 — Read the Graph
📊 V-T Graph 2 — More Practice
📊 David's Journey Home
This velocity-time graph shows David's journey home. Use the area under the graph to find how far away he lives.
💡 Scaffold — How to find the total distance
Break the graph into triangles, rectangles, and trapeziums. Find the area of each shape and add them together.
Triangle area = ½ × base × height | Rectangle = base × height | Trapezium = ½ × (a+b) × h
📊 Sonny's Journey to School
This velocity-time graph shows Sonny's journey to school. How far away does he live?
🎯 Final Quiz
📋 Instructions
Answer all 10 questions. Click an option to see if you're right. Your score will appear at the end!
Review any questions you got wrong — re-read the section and try to understand why before your next lesson.