Instantaneous Velocity Calculator - Formula & Function

Instantaneous Velocity Calculator

This instantaneous velocity calculator is used to calculate the velocity of an object at a particular instance for the given displacement and time.

What is Instantaneous Velocity?

"A velocity of an object at a given moment in time"

When an object moves with a uniform velocity, then its instantaneous velocity will be equal to the standard velocity.

How to Calculate Instantaneous Velocity?

It can be calculated using a formula that shows the instantaneous velocity which is the limit of the average velocity when the time interval tends towards zero.

Instant Velocity Formula:

Instantaneous Velocity = LimΔt → 0 x(t + Δt) - x(t) Δt

From the equation:

Instantaneous Velocity = dx (t) dt

Where:

• Δt = Smallest interval of the time
• x = Displacement
• t = Time
• d = Derivative of the position function

Example:

Suppose a car is moving along a straight path. Find how fast it is going at a specific moment by having a time of 3 seconds.

Car position is given by a function as:

x(t) = 5t2 + 2t + 4

Solution:

Step # 1: Use the Instantaneous velocity formula:

vint = dx(t) dt

Step # 2: Put the values into the formula:

vint = d(5t2 + 2t + 4) dt

Step # 3: Simplify the derivative

vint = 10t + 2

Put the value of (t)

vint = (10 * 3) + 2

vint= 32 ms-1

Hence, at 3 seconds the instantaneous velocity of a car is 32 ms-1. This means that the car’s position is changing at a rate of 32 meters every second at a specific moment.

Difference between Instantaneous Speed & Instantaneous Velocity:

➥ Instantaneous Speed:

Instantaneous speed is said to be the magnitude of instantaneous velocity

• Scalar quantity
• Formula of instantaneous speed is:

Speedint = ds dt

➥ Instantaneous Velocity:

Instantaneous velocity is the change of position which takes place at a small change in time

• Vector quantity
• Formula of instantaneous velocity is:

Vint = dx dt