Impulsive force: A force that acts on a body for a short period of time and results in an instant change in the momentum of the body is known as an Impulsive force. Consider a spring placed horizontally placed to a vertical wall, an object approaching it with some speed.
Let's analyze what's happening here, as soon as the object makes contact with the spring it starts experiencing the opposing force exerted by the spring.
The object's speed gets reduced and eventually comes to rest for an instant and starts moving in the opposite direction, all of this happens due to the constant opposing force exerted by the spring.
This opposing force varies with the deformation of the spring, But always there is some constant opposing force on the object.
Thus, this concludes springs exert constant varying force over a period of time which is considered to be non-impulsive as it's not instantaneous.
