Interactive physics simulator
Average Speed
Average speed tells how fast an object moves over a whole journey. It is calculated by dividing the total distance traveled by the total time taken.
Average Speed Simulator
Average speed uses the whole journey: add all distances, add all times, then divide.
Live Result
- Current segment / lap
- 1
- Segment distance
- 80 m
- Segment time
- 10 s
- Segment speed
- 8 m/s
- Total distance
- 180 m
- Total time
- 30 s
- Average speed
- 6 m/s
- Unit
- m/s
- Formula
- Average Speed = Total Distance / Total Time
What is Average Speed?
Average speed describes the complete journey. It adds every part of the distance traveled and divides by the total time taken, so it does not use displacement or direction.
Key Definition
Average speed is the total distance traveled divided by the total time taken.
- Average speed describes the whole journey.
- It uses total distance, not displacement.
- It uses total time.
- It is a scalar quantity.
- It has no direction.
- SI unit is meter per second, written as m/s.
Average Speed Formula
Average Speed = Total Distance / Total Time v_avg = d_total / t_total d_total = d1 + d2 + d3 + ... t_total = t1 + t2 + t3 + ... Variables and units
- v_avg = average speed
- d_total = total distance traveled
- t_total = total time taken
- distance in meters, time in seconds, average speed in m/s
Speed vs Average Speed
| Feature | Speed | Average Speed |
|---|---|---|
| Meaning | How fast something moves at a moment or over a simple interval. | How fast something moves over the whole journey. |
| Time period | Can describe a small part of motion. | Describes complete motion. |
| Uses | Distance and time for that part. | Total distance and total time. |
| Direction | No direction. | No direction. |
| Formula | Speed = distance / time. | Average Speed = total distance / total time. |
| Example | A car moving at 20 m/s now. | A trip of 300 km in 5 hours gives 60 km/h. |
Real-life Example of Average Speed
A bus travels 60 km in the first hour and 40 km in the second hour.
Total distance = 60 + 40 = 100 km Total time = 2 h Average speed = 100 / 2 = 50 km/h - A runner completes 400 m in 80 s.
- A cyclist rides 5 km in 20 minutes.
Solved Examples
View Solution: A car travels 100 m in 20 s. Find average speed.
Average Speed = Total Distance / Total Time
Average Speed = 100 / 20
Average Speed = 5 m/s
Final answer: 5 m/s
View Solution: A runner completes one 400 m lap in 80 s. Find average speed.
Average Speed = 400 / 80
Average Speed = 5 m/s
Final answer: 5 m/s
View Solution: A bus travels 60 km in 1 hour and 40 km in 1 hour. Find average speed.
Total distance = 60 + 40 = 100 km
Total time = 1 + 1 = 2 h
Average speed = 100 / 2 = 50 km/h
Final answer: 50 km/h
Common Mistakes
- Using displacement instead of total distance.
- Forgetting to add all distances.
- Forgetting to add all times.
- Taking a simple average of speeds when times are different.
- Mixing units like meters and kilometers.
- Forgetting time should be in seconds for SI unit.
- Adding direction even though average speed is scalar.
Quick Summary
- Average speed describes the whole journey.
- Formula: Average Speed = Total Distance / Total Time.
- It uses total distance.
- It uses total time.
- It is scalar and has no direction.
- SI unit is m/s.
- Average speed is never negative.
Practice Questions
1. Show Answer: A car travels 120 m in 12 s. Find average speed.
Step: Use Average Speed = Total Distance / Total Time when numbers are given.
Average speed = 120 / 12 = 10 m/s.
2. Show Answer: A runner completes 400 m in 100 s. Find average speed.
Step: Use Average Speed = Total Distance / Total Time when numbers are given.
Average speed = 400 / 100 = 4 m/s.
3. Show Answer: A bus travels 50 km in 1 hour and 70 km in 2 hours. Find average speed.
Step: Use Average Speed = Total Distance / Total Time when numbers are given.
Total distance = 120 km. Total time = 3 h. Average speed = 40 km/h.
4. Show Answer: A cyclist rides 300 m in 30 s. Find average speed.
Step: Use Average Speed = Total Distance / Total Time when numbers are given.
Average speed = 300 / 30 = 10 m/s.
5. Show Answer: Is average speed scalar or vector?
Step: Use Average Speed = Total Distance / Total Time when numbers are given.
Average speed is scalar because it has magnitude only and no direction.
6. Show Answer: Does average speed use distance or displacement?
Step: Use Average Speed = Total Distance / Total Time when numbers are given.
Average speed uses total distance, not displacement.
Frequently Asked Questions
What is average speed in physics?
Average speed is the total distance traveled divided by the total time taken.
What is the formula for average speed?
The formula is Average Speed = Total Distance / Total Time.
What is the SI unit of average speed?
The SI unit of average speed is meter per second, written as m/s.
Is average speed scalar or vector?
Average speed is a scalar quantity because it has magnitude only and no direction.
Can average speed be negative?
No. Average speed cannot be negative because total distance is never negative.
Does average speed use distance or displacement?
Average speed uses total distance traveled, not displacement.
Is average speed the same as velocity?
No. Average speed uses total distance and has no direction. Average velocity uses displacement and includes direction.
How does the average speed simulator work?
The simulator adds all distances, adds all times, and calculates average speed using total distance divided by total time.
Why is average speed not always the average of speeds?
If the object spends different amounts of time at different speeds, the simple average of speeds can be wrong. Average speed must use total distance divided by total time.
When is average speed equal to speed?
Average speed equals speed when an object moves at the same speed for the whole journey.