Jerk (physics)

Jerk is a measure of how fast something's speed is changing. Imagine you're in the backseat of a car and the driver suddenly slams on the brakes. You feel jerk because your body is used to traveling at a certain speed, but then it changes really quickly.

Jerk tells us how quickly that speed changes. When you're riding in a car and it's speeding up or slowing down really slowly, you don't feel much jerk. But if the car is accelerating or braking really sharply, you feel a lot of jerk.

So basically, jerk is a way to measure how fast something is changing its speed. It's named jerk because it describes that sudden, jarring feeling you get when you're suddenly thrown in a different direction.