> [!summary] Impulse is the change in linear momentum over time. > **Key Equations:** > Impulse in general: $I = \int_{t_i} ^ {t_f} F (t) dt$ > Impulse if force is constant: $I = F\Delta t$ >[!info]+ Read Time **⏱ 1 min** # Definition Impulse is the [[Rate of Change|change]] in [[Linear Momentum|linear momentum]] over time. It describes the change in forces over a time period. Sometimes impulse is denoted as $I$ or $J$ ## Derivation > [!warning] This definition uses that $F = \frac{dp}{dt}$ from [[Newton Laws|Newton's second law]] to simplify reasoning and math $\begin{array}{c} F = \frac{dp}{dt}\\ I = \int_{t_i} ^ {t_f} F(t)dt \\ \text{If F is consant the equation becomes} \\ I = F\Delta t \end{array}$ --- > 🧪 Think this could help someone else? [Star Math & Matter on Github](https://github.com/rajeevphysics/Obsidian-MathMatter) to help more learners discover it. ---