Instantaneous velocity

Definition

Instantaneous velocity is the velocity of an object at a specific moment in time. It is the derivative of the object's position with respect to time.

5 Must Know Facts For Your Next Test

1. Instantaneous velocity is a vector quantity, meaning it has both magnitude and direction.
2. Mathematically, it is represented as $v(t) = \frac{dx}{dt}$, where $x$ is the position and $t$ is time.
3. It can be found graphically as the slope of the tangent line to the position vs. time curve at a given point.
4. Unlike average velocity, instantaneous velocity concerns only a single point in time.
5. In uniform motion where acceleration is zero, instantaneous velocity remains constant.

Review Questions

• How do you mathematically represent instantaneous velocity?
• What does it mean when we say that instantaneous velocity is a vector quantity?
• How can you determine instantaneous velocity from a position vs. time graph?

Related terms

Average Velocity:

The total displacement divided by the total time taken. It gives an overall description of how fast something moves in a certain direction over a period.

Acceleration:

The rate of change of velocity with respect to time. It indicates how quickly an object speeds up or slows down.

Displacement:

A vector quantity that refers to the change in position of an object. It considers only the initial and final positions, not the path taken.