impulserna

Impulserna is a Swedish term meaning "the impulses" and may refer to several concepts across science and everyday language. The exact meaning depends on context.

In physics and engineering, impulse is the integral of force over time, J = ∫ F dt; it measures the instantaneous effect of a force on an object's momentum.

According to the impulse–momentum theorem, the impulse equals the change in momentum: J = Δp = m Δv. For constant force F over a time Δt, J = F Δt.

In physiology, nerve impulses (action potentials) are brief, all‑or‑none rises and falls in membrane potential that travel along neurons, enabling signaling between brain, nerves, and muscles. Myelination and axon diameter affect velocity.

In signal processing and systems theory, the impulse response describes how a system reacts to a brief input (an impulse). Through convolution, the system's output to any input is determined by its impulse response.

In everyday language, impulses refer to sudden urges or desires, such as impulse buying. Impulse control refers to the ability to resist such urges; impairments can contribute to behavioral disorders.

The term is used across disciplines to denote a brief, impactful influence—whether a force on a body, a neural signal, or a transient input to a system—reflecting the fast, momentary nature of the phenomenon.