Impulse

Objective: Explain the concepts and assumptions used in impulse.

Impulse is the time integral of net force; for constant or average net force, J=F_avgΔt. It equals momentum change. The same momentum change spread across more time requires a smaller average force magnitude. Direction and sign matter: a stopping impulse opposes initial momentum. Units N·s and kg·m/s are equivalent. A variable-force graph supplies impulse through its signed area, not simply peak force.

Objective: Apply impulse to calculations, evidence, and specified situations.

For the application problems, define the system and list the quantities supplied before choosing a relation. Use J=F_avgΔt; J=Δp. The relation must match the stated conditions. Convert to compatible units before substitution, preserve intermediate precision, and report the requested quantity with its unit or sign. When comparing alternatives, check the defining condition rather than a superficial word match. The worked examples below show the setup and calculation separately.