Speed and Velocity
Learn Speed and Velocity for GCSE Physics with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. Speed is how fast an object moves, while velocity is speed in a stated direction; typical walking speed is about 1.5 m/s.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Speed is the distance travelled per unit time and is a scalar. Velocity is the speed in a given direction and is a vector.
The equation is distance travelled = speed × time. It rearranges to give speed = distance ÷ time and time = distance ÷ speed, with distance in metres, time in seconds and speed in metres per second.
Because velocity is a vector, an object moving in a circle at constant speed has a continuously changing velocity, since its direction is always changing. This means it is accelerating, even though its speed never changes — a result students often find counter-intuitive.
Revision notes
Speed and velocity
Speed is the distance travelled per unit time — a scalar with no direction.
Velocity is the speed in a given direction — a vector. Two objects can have the same speed but different velocities if they travel in different directions.
The equation
Distance travelled = speed × time, s = vt.
Distance in metres, time in seconds, speed in metres per second. Rearranged: speed = distance ÷ time, and time = distance ÷ speed.
Circular motion
An object moving in a circle at constant speed has a continuously changing velocity.
Its direction changes at every instant, and velocity includes direction. A changing velocity means the object is accelerating, even though its speed is constant.
Key points
- Speed is a scalar; velocity is a vector.
- Velocity is speed in a given direction.
- Distance travelled = speed × time.
- Speed is measured in metres per second.
- Circular motion at constant speed has changing velocity.
- Changing velocity means acceleration.
Worked examples
Example 1
A car travels 300 m in 20 seconds. Calculate its speed. [2 marks]
Model answer
Speed = distance ÷ time = 300 ÷ 20 (1 mark) = 15 m/s (1 mark).
Example 2
Explain why an object moving in a circle at constant speed is accelerating. [3 marks]
Model answer
Velocity is a vector, so it includes direction as well as magnitude (1 mark). An object moving in a circle continuously changes direction, so its velocity is continuously changing (1 mark). A changing velocity means the object is accelerating (1 mark).
Example 3
A cyclist travels at 6 m/s for 40 seconds. Calculate the distance travelled. [2 marks]
Model answer
Distance = speed × time = 6 × 40 (1 mark) = 240 m (1 mark).
Common mistakes
Using speed and velocity interchangeably.
Velocity includes direction; speed does not.
Saying constant speed means no acceleration.
If the direction changes, the velocity changes and there is acceleration.
Forgetting to convert time to seconds.
Speed in m/s requires time in seconds.
Omitting units from the answer.
Speed must be given as m/s or similar.
Exam tips
- Say in a given direction when defining velocity.
- Convert time to seconds before calculating.
- Use the circular motion case to explain acceleration without changing speed.
- Include units in every answer.
Key terms
- Speed
- Distance travelled per unit time, a scalar.
- Velocity
- Speed in a given direction, a vector.
- Acceleration
- A change in velocity.
- Metres per second
- The standard unit of speed.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.