Interactive physics simulator
Velocity
Velocity tells how fast an object changes its position in a specific direction. It is calculated by dividing displacement by time.
Velocity Simulator
Live Result
- Start
- 0 m
- End
- 100 m
- Displacement
- 100 m
- Time
- 10 s
- Timer
- 0 s
- Velocity
- 10 m/s east
- Speed
- 10 m/s
- Direction
- east
- Unit
- m/s
- Formula
- Velocity = Displacement / Time
What is Velocity?
Velocity is speed with direction. In physics, it uses displacement, not total distance, so two motions can have the same speed but different velocity if their directions or final positions are different.
Key Definition
Velocity is the rate of change of displacement with time.
- Velocity tells speed with direction.
- Velocity is a vector quantity.
- Velocity can be positive, negative, or zero.
- SI unit of velocity is meter per second (m/s).
- Direction is important in velocity.
Velocity Formula
Velocity = Displacement / Time v = Δx / t Δx = x₂ - x₁ Average velocity = total displacement / total time Variables and units
- v = velocity
- Δx = displacement
- t = time
- displacement in meters, time in seconds, velocity in m/s
Speed vs Velocity
| Feature | Speed | Velocity |
|---|---|---|
| Meaning | Distance covered per time | Displacement per time |
| Quantity type | Scalar | Vector |
| Direction | No direction | Has direction |
| Can be negative? | Cannot be negative | Can be positive, negative, or zero |
| Formula | Speed = distance / time | Velocity = displacement / time |
| Example | 10 m/s | 10 m/s east |
Real-life Example of Velocity
A car moves 100 meters east in 10 seconds.
Displacement = 100 m east Time = 10 s Velocity = 100 / 10 = 10 m/s east - A runner returns to the starting point: average velocity is zero.
- A car moving west may have negative velocity if east is chosen as positive direction.
Solved Examples
View Solution: A car moves 60 m east in 6 s. Find velocity.
Velocity = displacement / time. Velocity = 60 / 6 = 10 m/s east.
Final answer: 10 m/s east
View Solution: An object moves from x = 20 m to x = 5 m in 5 s. Find velocity.
Displacement = 5 - 20 = -15 m. Velocity = -15 / 5 = -3 m/s.
Final answer: -3 m/s
View Solution: A runner travels around a track and returns to the starting point in 40 s. Find average velocity.
Displacement = 0 m. Average velocity = 0 / 40 = 0 m/s.
Final answer: 0 m/s
Common Mistakes
- Confusing speed with velocity.
- Forgetting direction.
- Using distance instead of displacement.
- Forgetting that velocity can be negative.
- Forgetting to include time in seconds.
- Writing velocity without direction when direction is needed.
- Thinking speed and velocity are always equal.
Quick Summary
- Velocity means speed with direction.
- Formula: Velocity = Displacement / Time.
- Velocity is vector.
- SI unit is m/s.
- Direction matters.
- Velocity can be positive, negative, or zero.
- Average velocity can be zero even if distance traveled is not zero.
Practice Questions
1. Show Answer: A car moves 80 m east in 8 s. Find velocity.
Step: Use displacement and time. Include direction when needed.
Velocity = 80 / 8 = 10 m/s east.
2. Show Answer: An object moves from x = 10 m to x = 30 m in 5 s. Find velocity.
Step: Use displacement and time. Include direction when needed.
Displacement = 30 - 10 = 20 m. Velocity = 20 / 5 = 4 m/s.
3. Show Answer: An object moves from x = 20 m to x = 0 m in 4 s. Find velocity.
Step: Use displacement and time. Include direction when needed.
Displacement = 0 - 20 = -20 m. Velocity = -20 / 4 = -5 m/s.
4. Show Answer: A runner returns to the start after 60 s. What is average velocity?
Step: Use displacement and time. Include direction when needed.
Average velocity is 0 m/s because displacement is 0 m.
5. Show Answer: Is velocity scalar or vector?
Step: Use displacement and time. Include direction when needed.
Velocity is vector because it has magnitude and direction.
6. Show Answer: What is the difference between speed and velocity?
Step: Use displacement and time. Include direction when needed.
Speed uses distance and has no direction. Velocity uses displacement and includes direction.
Frequently Asked Questions
What is velocity in physics?
Velocity is the rate of change of displacement with time. It tells how fast an object changes position and in which direction.
What is the formula for velocity?
The formula for velocity is Velocity = Displacement / Time, or v = Δx / t.
What is the SI unit of velocity?
The SI unit of velocity is meter per second, written as m/s.
Is velocity scalar or vector?
Velocity is a vector quantity because it has both magnitude and direction.
What is the difference between speed and velocity?
Speed uses distance and has no direction. Velocity uses displacement and includes direction.
Can velocity be negative?
Yes. Velocity can be negative if the object moves in the negative direction according to the chosen coordinate system.
Can velocity be zero while speed is not zero?
Average velocity can be zero if the object returns to its starting point, even though it traveled some distance and had speed during the motion.
How does the velocity simulator work?
The simulator uses the start position, end position, and time to calculate displacement and velocity. It shows direction using an arrow.
Why is time important in velocity?
Time is needed because velocity measures how much displacement happens per unit of time.
When are speed and velocity the same?
Speed and velocity have the same magnitude when an object moves in a straight line without changing direction.