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Average Velocity

Average velocity tells how fast an object changes its position in a specific direction over a whole journey. It is calculated by dividing total displacement by total time.

Average Velocity Simulator

Average velocity uses displacement and total time. The orange path can be long, but the blue arrow decides average velocity.

Live Result

Start
Floor 2
End
Floor 6
Total distance
12 m
Displacement
12 m
Total time
10 s
Timer
0 s
Average speed
1.2 m/s
Average velocity
1.2 m/s upward
Direction
upward
Unit
m/s
Formula
Average Velocity = Displacement / Time

What is Average Velocity?

Average velocity describes the whole journey using only the change in position and the total time. It does not use the full path length, so an object can travel a long distance and still have zero average velocity if it returns to the starting point.

Key Definition

Average velocity is total displacement divided by total time.

  • Average velocity describes the whole journey.
  • It uses displacement, not total distance.
  • It includes direction.
  • It is a vector quantity.
  • It can be positive, negative, or zero.
  • SI unit is meter per second, written as m/s.

Average Velocity Formula

Main formula Average Velocity = Total Displacement / Total Time
Symbol form v_avg = Δx / t
2D displacement Displacement = sqrt((x2 - x1)^2 + (y2 - y1)^2)
Direction θ = tan^-1((y2 - y1) / (x2 - x1))
Variables and units
  • v_avg = average velocity
  • Δx = displacement
  • t = total time
  • displacement in meters, time in seconds, average velocity in m/s

Average Speed vs Average Velocity

FeatureAverage SpeedAverage Velocity
UsesTotal distanceDisplacement
TypeScalarVector
DirectionNo directionHas direction
Can be zero after motion?Usually not zero if motion happenedCan be zero if final position equals start
Can be negative?Never negativeCan be positive, negative, or zero in 1D
FormulaTotal distance / total timeTotal displacement / total time
ExampleRunner completes one lap: average speed is distance/timeRunner completes one lap: average velocity is 0

Real-life Example of Average Velocity

A hiker walks around a park and ends 30 meters east from the starting point in 10 seconds.

Displacement = 30 m east Total time = 10 s Average velocity = 30 / 10 = 3 m/s east
A B orange path = distance blue arrow = displacement
  • An elevator moves from floor 2 to floor 6 in 8 seconds.
  • A runner completes one full lap and returns to the start, so average velocity is zero.

Solved Examples

View Solution: A person moves 50 m east in 10 s. Find average velocity.

Average velocity = displacement / time

Average velocity = 50 / 10 = 5 m/s east

Final answer: 5 m/s east

View Solution: An elevator moves from floor 1 to floor 5. Each floor is 3 m high. The time taken is 12 s. Find average velocity.

Displacement = (5 - 1) x 3 = 12 m upward

Average velocity = 12 / 12 = 1 m/s upward

Final answer: 1 m/s upward

View Solution: A runner completes one full lap of a track in 40 s and returns to the starting point. Find average velocity.

Displacement = 0 m

Average velocity = 0 / 40 = 0 m/s

Final answer: 0 m/s

Common Mistakes

  • Using total distance instead of displacement.
  • Forgetting direction.
  • Confusing average speed with average velocity.
  • Thinking average velocity cannot be zero after motion.
  • Forgetting total time must be used.
  • Forgetting units.
  • Ignoring positive and negative direction.

Quick Summary

  • Average velocity describes the whole journey.
  • Formula: Average Velocity = Total Displacement / Total Time.
  • It uses displacement, not distance.
  • It includes direction and is vector.
  • SI unit is m/s.
  • It can be positive, negative, or zero.
  • If final position equals starting position, average velocity is zero.

Practice Questions

1. Show Answer: A student moves 40 m north in 8 s. Find average velocity.

Step: Use displacement and total time. Include direction when it is given.

Average velocity = 40 / 8 = 5 m/s north.

2. Show Answer: An elevator moves from floor 2 to floor 7. Each floor is 3 m. Time is 15 s. Find average velocity.

Step: Use displacement and total time. Include direction when it is given.

Displacement = (7 - 2) x 3 = 15 m upward. Average velocity = 15 / 15 = 1 m/s upward.

3. Show Answer: A runner completes one full lap and returns to the start in 60 s. What is average velocity?

Step: Use displacement and total time. Include direction when it is given.

Average velocity is 0 m/s because displacement is 0 m.

4. Show Answer: Does average velocity use distance or displacement?

Step: Use displacement and total time. Include direction when it is given.

Average velocity uses displacement, not total distance.

5. Show Answer: Is average velocity scalar or vector?

Step: Use displacement and total time. Include direction when it is given.

Average velocity is vector because it has magnitude and direction.

6. Show Answer: Can average velocity be zero even when distance is not zero?

Step: Use displacement and total time. Include direction when it is given.

Yes. If the final position equals the starting position, displacement is zero, so average velocity is zero.

Questions

Frequently Asked Questions

What is average velocity in physics?

Average velocity is total displacement divided by total time. It tells how fast position changes in a specific direction over a whole journey.

What is the formula for average velocity?

The formula is Average Velocity = Total Displacement / Total Time, or v_avg = Δx / t.

What is the SI unit of average velocity?

The SI unit of average velocity is meter per second, written as m/s.

Is average velocity scalar or vector?

Average velocity is a vector quantity because it has magnitude and direction.

Does average velocity use distance or displacement?

Average velocity uses displacement, not total distance.

Can average velocity be zero?

Yes. Average velocity is zero if the final position is the same as the starting position.

Can average velocity be negative?

Yes. In one-dimensional motion, average velocity can be negative if displacement is in the negative direction.

What is the difference between average speed and average velocity?

Average speed uses total distance and has no direction. Average velocity uses displacement and includes direction.

How does the average velocity simulator work?

The simulator uses start position, final position, and total time to calculate displacement and average velocity.

Why can a runner have average velocity zero after running a lap?

If the runner returns to the starting point, displacement is zero, so average velocity is zero even though distance was traveled.