Impulse: A Push, in Physics and in the Mind
An impulse is a sudden urge to act, and in physics a force applied over a short time. Both are pushes that change what happens next.
An impulse is a sudden urge that arrives before the reasoning does. Physics uses the same word precisely: an impulse is a force multiplied by the time it acts, which is why a short shove changes a ball's motion. Mental and mechanical impulses both mean a push that alters the course of things.
- A sudden urge to act. *He bought it on impulse.*
- A push or driving force. *An impulse to reform.*
- A force acting briefly (physics). *The impulse of the collision.*
- A signal in a nerve or circuit. *Electrical impulses.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | impulse | A sudden impulse. |
| Plural | impulses | Nerve impulses. |
| Adjective | impulsive | An impulsive decision. |
| Adverb | impulsively | She acted impulsively. |
| Compound | impulse buy | An impulse buy. |
How it is used in a sentence
- I called her on impulse.On impulse, without an article.
- Sweets by the till are there for impulse buys.Retail design depends on it.
- Nerve impulses travel at up to 120 metres a second.The biological sense.
Impulse and its relatives
- Impulse — a sudden urge or a brief force
- Instinct — an inborn pattern of behaviour
- Whim — a passing fancy, lighter than an impulse
- Compulsion — an urge that feels impossible to resist
- Momentum — what an impulse changes
From Latin *impulsus*, a push, from *impellere*, to drive on, from *in* and *pellere*, to push — the same root as *propel*, *compel* and *repel*.
Impulse or impulsive?
Impulse is the urge itself; impulsive describes a person or act driven by such urges.
What is impulse in physics?
Force multiplied by the time it acts. It equals the change in momentum it produces.