# Impulse vs. Force: What's the Difference?

Edited by Aimie Carlson || By Janet White || Published on December 22, 2023
Impulse is the product of force and the time over which it acts, while force is an interaction that changes the motion of an object.

## Key Differences

Impulse is defined as the change in momentum of an object when a force is applied over a period of time. Force, on the other hand, is the push or pull on an object that causes its velocity to change.
The unit of impulse is Newton-seconds (Ns), which combines force (measured in Newtons) and time (in seconds). Force is measured in Newtons, representing the rate of change of momentum.
Impulse is calculated by multiplying force by the time duration it is applied. Force is calculated as mass times acceleration, according to Newton's second law.
An impulse can either increase or decrease the velocity of an object. Force can be categorized as contact or non-contact, influencing an object’s state of motion.
The concept of impulse is especially useful in understanding collisions and impacts. Force is fundamental in studying dynamics and statics in physics.

## Comparison Chart

### Definition

Product of force and time over which it acts
Interaction that changes an object’s motion

### Units

Newton-seconds (Ns)
Newtons (N)

### Calculation

Force multiplied by time
Mass multiplied by acceleration

### Role in Physics

Important in analyzing impacts and collisions
Fundamental in dynamics, statics, and kinematics

### Effect on Objects

Changes the object's momentum
Causes or changes acceleration

## Impulse and Force Definitions

#### Impulse

Impulse is the total effect of a force acting over time.
The boxer's punch delivered a strong impulse to the bag.

#### Force

Force is a vector quantity, having both magnitude and direction.
The wind exerted a strong force against the sails of the boat.

#### Impulse

In physics, impulse is the integral of force with respect to time.
The longer impulse duration lessened the impact on the catcher’s mitt.

#### Force

In physics, force is what causes an object with mass to change its velocity.
He applied a force to the door to open it.

#### Impulse

Impulse is a measure of the change in momentum.
The impulse applied to the car caused a significant change in its speed.

#### Force

Force is central to the study of mechanics and physics.
Magnetic force causes attraction between opposite poles of magnets.

#### Impulse

Impulse is the product of the average force and the time period over which it acts.
The rocket's engines provided a sustained impulse to escape Earth's gravity.

#### Force

Force can initiate motion, stop motion, or change the direction of motion.
The brakes exert a force to slow down the vehicle.

#### Impulse

Impulse can be understood as the forceful interaction occurring briefly.
The impulse from the collision was enough to push the object off the table.

#### Force

Force is a push or pull upon an object resulting from its interaction with another object.
The force of gravity keeps us anchored to the Earth.

#### Impulse

An impelling force; an impetus.

#### Force

The capacity to do work or cause physical change; energy, strength, or active power
The force of an explosion.

#### Impulse

The motion produced by such a force.

#### Force

Power made operative against resistance; exertion
Use force in driving a nail.

## FAQs

#### Is force always constant in generating an impulse?

Not necessarily; force can vary over the time period it's applied.

#### What is impulse in simple terms?

Impulse is the effect of a force acting over a period of time.

#### Can impulse exist without force?

No, impulse is directly related to force; it cannot exist without force.

#### Is acceleration necessary for a force?

Yes, force causes or changes acceleration of an object with mass.

#### Is impulse a vector quantity?

Yes, like force, impulse is also a vector quantity, having both magnitude and direction.

#### How do you measure impulse?

Impulse is measured in Newton-seconds, calculated as force times time.

#### Can impulse be negative?

Yes, if the force reduces the object’s momentum.

#### How is force different from impulse?

Force is the push or pull on an object, while impulse is the product of force and the time over which it acts.

#### What units are used to measure force?

Force is measured in Newtons.

#### What types of forces are there?

Forces can be contact (like friction) or non-contact (like gravity).

#### Are impulse and momentum the same?

No, but impulse is directly related to the change in momentum.

#### What happens when a force is applied for a longer time?

Applying a force for a longer time increases the impulse.

#### Can two different forces produce the same impulse?

Yes, if the product of force and time is the same.

#### Can impulse be seen in everyday life?

Yes, whenever a force is applied over time, like hitting a ball, impulse occurs.

#### Is it possible to have force without motion?

Yes, forces can be balanced, resulting in no motion, like in static equilibrium situations.

#### Can impulse change an object’s direction?

Yes, if the force applied changes the object's momentum direction.

#### How does force affect an object’s state of motion?

Force can initiate, stop, or alter the direction of an object's motion.

#### Can the same force produce different impulses?

Yes, depending on how long the force is applied, the resulting impulse can vary.

#### How does force relate to Newton's laws of motion?

Force is central to Newton's laws, explaining how objects move and interact.

#### What role does time play in creating an impulse?

The duration of force application is crucial in determining the magnitude of impulse.