Impulse Formula

Download PDF

Impulse Definition and Formula

Bookmark added to your notes.
View Notes

We all see the delicate items like glass products rolled with a newspaper around them, ordered purchased items packed in air-bubbled plastic sheets.

(Image to be added soon)       

By doing this, the impulse increases (product remains damage-free) because of which the downward force on the object decreases with the increase in time.                    

An impulse is the inverse of the force. It means the magnitude of impulse formula depends on the force and the change in time.

In this article, we will discuss the impulse formula.

Impulse Formula Physics

Now, let’s discuss the impulse formula in detail:

In the above impulse formula topic, we discussed that all delicate items are rolled in the newspaper or an air-bubbled plastic sheet. The reason is by chance the item falls on the floor, the force will first reach the rolled newspaper/sheet and then, it reaches the item.

We notice that the effect of downward force was maximum while reaching the newspaper/effect and eventually it reduces when it reaches the item. So, in this scenario, the time increases. It means that the effect of force reduces with the rise in time.

We notice that the magnitude of impulse increases with time; however, the effect of force reduces with the rise in time and impulse. The impulse equation for this context goes like this:

Impulse Equation

                       J = F.Δt…(1) (It is the required Linear Impulse Formula)


‘J’ is the impulse and it is directly proportional to time and inversely proportional to the subjected force ‘F’.

Impulse ‘J’ is measured in N.s. Now, let’s understand the dimensional formula of impulse ‘J’.

Dimensional Formula of Impulse 

We know that the impulse Physics equation is given by:

                  J = F.Δt


F is measured in Newton and its dimensional formula is [M1L1T-1].

Δt is measured in seconds and its dimensional formula is [M0L0T1]. 

Now, putting the value of eq (2) and (3) in eq (1), we get the dimensional formula of impulse as:

              = [M1L1T-2] * [M0L0T1]

On solving the above equation, we get the following dimensional formula:

             = [M1L1T-1] is the required dimension of the impulse formula.

Impulse Momentum Equation

The following impulse momentum equation can be used to calculate Impulse: 

  J = m * Δv

In simple words,

Impulse = mass (m) * (Velocity2-Velocity1)

Where velocity1 & velocity2 are velocities at two different points in a given time interval. In other words, we call it the change in velocity.

The unit of impulse according to the above equation can be calculated in the following manner:

Mass = in kg

Velocity = in m/s

   J   = kg . m/s or N.s 


The unit and the dimensional formula for impulse remains the same in the case of the following equations:

  • J = F * Δt   

  • J = m * Δv

 Impulse is the safeguard of delicate items against the external force.    

FAQ (Frequently Asked Questions)

1. What is the linear impulse in Physics?

The linear impulse is a vector quantity that is exerted by a force in a given time interval ‘t’, it can be expressed as the force as a function of time. You can calculate the linear impulse using simple calculus.

2. What is the impulse-momentum relationship?

According to Newton’s second law of motion:

                    F = dp/dt

Putting this value in J = F.dt, we get:

                  J = dp or mdv.

3. What is linear momentum?

A linear momentum is a vector quantity, which acts on the object of mass ‘m’ moving with velocity ‘v’. Its equation is given by:

                         p = mv

Here, p is the linear momentum of an object measured in kgm/s. The direction of linear momentum remains parallel to the direction of the object’s velocity.