SIMPLIFIED: "4.3: Impulse"

Link: https://phys.libretexts.org/Bookshelves/Conceptual_Physics/Introduction_to_Physics_(Park)/03%3A_Unit_2-_Mechanics_II_-_Energy_and_Momentum_Oscillations_and_Waves_Rotation_and_Fluids/04%3A_Impulse_and_Momentum/4.03%3A_Impulse 

Note: The above image is from the original article.

The article linked above talks about impulse! In the physics world, impulse is the change in momentum of an object due to a force being exerted on that object for an interval of time. The mathematical equation for impulse is: J = F times (change in time). In that equation, J represents impulse (not joules), F represents the force, and the change in time is… well, the change in time. 

Impulse is a concept usually taught with momentum. This is because impulse can also be defined as the change in momentum. Therefore, impulse tells us how much the momentum of an object has changed. Additionally, if you graph force on the y-axis and then time on the x-axis, you can take the area under the curve of that graph to find the impulse. 

Here is an everyday example of impulse. Let’s say someone throws a water balloon at you. If you just catch the water balloon as if you were to regularly catch a basketball, the water balloon would probably explode in your hands. However, if you were to move your hands downwards and catch the water balloon as if you were cradling a baby, then the water balloon is more likely not to explode. This is because the amount of time the water balloon is in your hands increases, and therefore the force decreases because the impulse is the same. 

Impulse is actually the main reason why cars have airbags. When an airbag is released during a car crash, it will take your body a longer amount of time to stop, which means the amount of force on your body will decrease because the change in momentum is the same. Increasing the change in time in the time interval ultimately reduces the force experienced by you or an object, which is why it is important to study this concept in the first place.