✓ Revise Right course
Distance is calculated with s = vt, distance = speed × time. Free GCSE AQA Physics revision notes with key definitions, plus 6 common questions answered.
Distance, Displacement and Speed (Part 2/3) is part of Forces and motion in GCSE AQA Higher Physics.
5 min
Reading time
39
Lessons in this topic
GCSE AQA Higher
Pathway
Reviewed by Revise Right
Content review
Distance is calculated with s = vt, distance = speed × time. Free GCSE AQA Physics revision notes with key definitions, plus 6 common questions answered.
AQA GCSE Physics mock draft, 26–31 Oct. Draft coverage: Physics Paper 1 (Higher tier). Reviewed for an original-practice sitting; check student availability before registering. Marking and results will follow later, after separate approval. Eligible new accounts receive a five-day Pro trial when signup email verification completes. Previous trials keep their original expiry. After expiry, new papers need Pro unless you have an explicitly confirmed free sitting offer for this event. That offer adds no Pro time or AI learning. Saved attempts and released results remain readable. No card or automatic charge.
Use this lesson to stay inside Forces and motion while connecting the detail back to the wider Forces topic.
Read the core explanations from Distance, Displacement and Speed (Part 2/3) before testing yourself from memory.
You walk to school, cycle to the shops, or travel by car on the motorway. Each journey involves different speeds, but how do we measure and compare them scientifically?
Speed isn't just about moving objects. Sound travels through air at roughly 330 m/s, which is why you see lightning before hearing thunder. Wind speed varies from gentle breezes to hurricane-force gales.
Understanding typical speed values helps you spot unrealistic answers in calculations. A person running at 100 m/s would be moving faster than a car on the motorway - clearly impossible!
Here are the typical speeds you need to memorise for your exam. These values appear regularly in GCSE questions, so knowing them saves time and helps you check your answers make sense.
| Motion Type | Typical Speed |
|---|---|
| Person walking | 1.5 m/s |
| Person running | 3 m/s |
| Person cycling | 6 m/s |
| Car in town | 13 m/s (30 mph) |
| Car on motorway | 31 m/s (70 mph) |
| Train | 55 m/s |
| Aircraft | 250 m/s |
| Sound in air | 330 m/s |
When an object moves at constant speed, it covers the same distance every second. This creates a simple relationship between three quantities: speed, distance, and time.
Think of it like this: if you walk at 2 m/s for 10 seconds, you'll travel 20 metres. The faster you go, or the longer you travel, the further you get.
You can rearrange this equation to find any of the three quantities. If you know distance and time, divide to find speed: $v = \frac{s}{t}$. If you know speed and distance, divide to find time: $t = \frac{s}{v}$.
Speed calculations follow a clear method that earns you marks even if your final answer is wrong. Examiners award method marks for showing the correct formula and substitution.
The key is to write down what you know, what you need to find, and then substitute carefully with units. Let's work through a typical exam question.
Worked example: Calculating Speed from Distance and Time
A car travels 450 m in 18 s. Calculate its speed. [3 marks]
Answer: 25 m/s
Notice how each step earns marks. Even if you make an arithmetic error in step 4, you still get 2 out of 3 marks for showing the correct method.
Always check your answer makes sense. 25 m/s is roughly the speed of a car on a main road - reasonable for this problem. If you'd calculated 250 m/s, you'd know something was wrong.
Sometimes you know the speed and time, and need to find the distance travelled. This uses the original form of our equation: $s = vt$.
This calculation is particularly useful for planning journeys or working out stopping distances. Remember to keep your units consistent throughout.
Worked example: Finding Distance from Speed and Time
A cyclist travels at 8 m/s for 25 s. How far does she travel? [3 marks]
Answer: 200 m
The cyclist travels 200 metres, which is about the length of two football pitches. This seems reasonable for cycling at moderate speed for 25 seconds.
Unit trap: If the time had been given in minutes, you'd need to convert to seconds first. Always work in metres, metres per second, and seconds unless told otherwise.
In real experiments, you need to measure both distance and time accurately to calculate speed. The equipment you choose affects the precision of your results.
For measuring distance, use a metre rule for short distances or a trundle wheel for longer ones. For time, stopwatches work for slow-moving objects, but you'll need light gates for faster motion.
Human reaction time introduces errors when using stopwatches. Your finger takes about 0.2 seconds to respond to what your eyes see, which matters for quick measurements.
Light gates give more accurate timing because they eliminate human reaction time. They use infrared beams that automatically start and stop timing when objects pass through.
Speed questions are mark-friendly if you follow the method. Examiners look for three things: correct formula, proper substitution with units, and a sensible final answer.
Common mistakes include forgetting units, mixing up the formula triangle, and not converting time units. Let's tackle these systematically.
The formula triangle helps you remember rearrangements. Put distance ($s$) at the top, speed ($v$) and time ($t$) at the bottom. Cover what you want to find - the remaining letters show you the calculation.
For 6-mark questions, you'll need to combine speed calculations with other physics concepts. Practice linking speed to kinetic energy, stopping distances, or wave properties.
Remember that speed is a scalar quantity - it has magnitude but no direction. When direction matters, we use velocity instead, but that's covered in the next part of this topic.
Published by Revise Right. Use the official specification reference to check the requirements for your course. Content updated: 2026-03-20.
Move to the related lessons or back to the topic page when you need the wider sequence before exam-style practice.
Distance is calculated with s = vt, distance = speed × time. A cyclist travelling at 8 m/s for 25 s travels 8 × 25 = 200 m; convert any time in minutes to seconds first.
Sound travels through air at roughly 330 m/s, faster than an aircraft at about 250 m/s. This is why lightning is seen before thunder is heard, and knowing typical values like this helps spot unrealistic answers in calculations.
Constant speed is motion where an object covers equal distances in equal time intervals. Walking at 2 m/s for 10 seconds at constant speed covers 20 metres.
Typical speeds are about 13 m/s (30 mph) for a car in town, 31 m/s (70 mph) for a car on the motorway, 55 m/s for a train and 250 m/s for an aircraft. Sound in air travels at about 330 m/s.
The speed equation v = s/t rearranges to s = vt to find distance and t = s/v to find time. In the formula triangle, distance (s) goes at the top with speed (v) and time (t) at the bottom; covering the quantity needed shows the calculation.
Light gates are more accurate because they use infrared beams that start and stop timing automatically, so there is no human reaction time. With a stopwatch, a finger takes about 0.2 seconds to respond, which matters for quick measurements.
A typical car in town travels at about 13 m/s (30 mph), and a car on the motorway at about 31 m/s (70 mph). A train is about 55 m/s and an aircraft about 250 m/s.
A car that travels 450 m in 18 s has a speed of 25 m/s. Using v = s/t, v = 450 ÷ 18 = 25 m/s, which is roughly the speed of a car on a main road.
Distance is measured with a metre rule for short distances or a trundle wheel for longer ones. Time is measured with a stopwatch for slow-moving objects, but light gates are needed for faster motion.
A train travels at a typical speed of about 55 m/s, compared with about 31 m/s for a car on the motorway and about 250 m/s for an aircraft.
Unrealistic speed answers show up when compared with typical speeds: a person running at 100 m/s would be faster than a car on the motorway, which is clearly impossible. A calculated car speed of 250 m/s would also signal an error.
Time must be in seconds for speed in m/s, so minutes are converted to seconds first. Calculations should use metres, metres per second and seconds unless told otherwise.