Instantaneous Velocity
Reference from the original Physics I textbook.
- Instantaneous Velocity
Instantaneous velocity is the rate of change of position at a particular time: v⃗ = dr⃗/dt. A car’s speedometer gives speed, |v⃗|; velocity also requires a direction relative to a chosen frame.
- Related Glossary Terms
- Index
Reviewed physics notes (1)
These corrections keep the original lesson’s purpose while fixing errors in the source edition.
- Speedometer measures speed rather than velocity. — Reference 1
Glossary and deeper reading · 2 refreshers
These editorial refreshers supplement the reading. Definitions and examples are added guidance; original source wording and recorded answers remain in their original context.
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Instantaneous velocity
Instantaneous velocity is the rate of change of position at a particular moment. On a position-versus-time graph, its component is the slope of the tangent at that time. For example, the velocity just before a ball lands differs from the average velocity of its entire flight.
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Velocity
Velocity describes how position changes with time and includes direction. Instantaneous velocity describes one moment, while average velocity is displacement divided by elapsed time. For example, a car turning a corner can change velocity while maintaining the same speed.