Units check: what is the correct unit of impulse in mechanics? Select the correct unit for linear impulse (impulse of a force) in SI-consistent terms.

Introduction / Context:
Impulse equals the integral of force over time and measures the change in linear momentum imparted to a body. Correct units confirm dimensional consistency in impact, crash, and propulsion calculations.

Given Data / Assumptions:

• Linear impulse J = ∫ F dt.
• In SI, force F has units of Newtons (N) and time t in seconds (s).
• Momentum p has units kg·m/s, and J = Δp.

Concept / Approach:

Because impulse equals change in momentum, its unit must match momentum. Alternatively, multiply N by s to obtain N·s. Since 1 N = 1 kg·m/s^2, N·s = kg·m/s.

Step-by-Step Solution:

Verification / Alternative check:

Check with momentum: p = m v, units kg·m/s. Since J = Δp, the unit alignment is exact.

Why Other Options Are Wrong:

(b) kg·m/s^3 corresponds to power per unit force; (c) kg·m/s^2 is force; (d) kg·m^2/s is not momentum; (e) N·m is work/torque, not impulse.

Common Pitfalls:

Confusing N·s (impulse) with N·m (work/torque); forgetting impulse equals momentum change.

Final Answer:

kg·m/s