Impulse is a very subtle and little known aspect of our daily lives. Impulse can be seen in a variety of things such as cars to projectiles to rockets to sports and so on. In sports, American Football, Volleyball, Basketball, and about every other sport, impulse is implemented. For instance, one can observe impulse in his/her shoes: the cushion between the floor and one’s foot reduces the amount of force done on the foot from a reactionary force. The same data can be observed in padded sleeves: knee pads in Volleyball, compression wear in Football, jockstraps, and so on.
Impulse is a vector quantity defined as the product of the force acting on a body and the time interval during which the force is exerted. Impulse is part of Newton’s Second Law and goes hand in hand with momentum. The S.I. unit for Impulse is the Newton-Second.
A force causes acceleration and a change in the velocity for as long as it acts. Therefore, a resultant force that is applied over a longer period of time will produce a bigger change in linear momentum than the same force applied briefly: the change in momentum is equal to the product of the average force and duration. The same effect works vice-versa: a small force applied for a long time produces the same change in momentum (or the same change in impulse) as a larger force applied briefly. For example, in American Football, a linebacker will charge and tackle the quarterback. The force from the impact can potentially cause concussions or even break bones if the quarterback isn’t covered in paddings and protective gear. However, a force can be great enough to cause the previously stated injuries. Assume there is a 150 kilogram (kg) linebacker charging at a quarterback at 5 meters per second (m/s), the linebacker would apply a force of 750 newtons (N): Force = Mass x Acceleration. Now, compare this force to a 12-gauge shotgun, whose shrapnel would apply a force of approximately 500 m/s. As one can see, the amount of force that the linebacker applies is tremendous. However, the linebacker doesn’t apply that true amount of force. With a series of paddings and/or cushionings, the force is reduced to a minimal. The longer it takes for the force to go through the padding and connect to the body, the less force a person will receive. For example, if it takes 3 seconds for the force to connect, the force will be reduced to 250 N.
To conclude, Impulse is a fundamental that allows most aspects of our daily lives.