Enter the inertial mass, change in velocity, and change in time into the calculator to determine the inertia force.

Inertia Force Formula

The following equation is used to calculate the Inertia Force.

IF = IM * V/T
  • Where If is the inertia force (N)
  • IM is the inertial mass (kg)
  • V is the change in velocity (m/s)
  • T is the change in time (s)

To calculate the inertia force, multiply the inertial mass by the division of the change in velocity over the change in time.

What is an Inertia Force?


An inertia force is a force acting on an object that causes its velocity to change. Inertia is a measure of the resistance of an object to change velocity. The greater the mass of an object, the greater the inertia.

How to Calculate Inertia Force?

Example Problem:

The following example outlines the steps and information needed to calculate the Inertia Force.

First, determine the inertial mass. In this example, the inertial mass is found to be 15kg.

Next, determine the change in velocity. For this problem, the change in velocity is found to be 3m/s.

Next, determine the change in time. In this case, the change in time is measured to be 2 seconds.

Finally, calculate the Inertia Force using the formula above:

IF = IM * V/T

IF = 15 * 3/2

IF = 22.5 N


What is the difference between inertia force and gravitational force?

Inertia force is a pseudo force that arises due to the resistance of an object to change in its state of motion or rest, and it depends on the mass of the object and the acceleration it undergoes. Gravitational force, on the other hand, is a real force that attracts two bodies towards each other, depending on their masses and the distance between them.

Can inertia force be negative?

Yes, inertia force can be considered negative in scenarios where the direction of the acceleration is opposite to the direction of motion. This is because the inertia force is directly related to the acceleration, and a change in the direction of acceleration affects the direction of the inertia force.

How does the mass of an object affect its inertia force?

The mass of an object is directly proportional to its inertia force. This means that the greater the mass of an object, the greater its inertia force. This is because a more massive object requires a greater force to change its state of motion or rest compared to a less massive object.