Momentum's unit from mass and velocity

Steps:

• Recall momentum definition: product of mass and velocity.
• Identify mass unit: kilograms (kg).
• Identify velocity unit: meters per second (m/s).
• Combine units: kg × m/s = kg m/s.

Why A is correct:

• Momentum p = m v, so its SI unit is kg m/s by direct multiplication of mass and velocity units.

Why the others are wrong:

• B: kg m/s² is the unit for force (Newton's second law, F = ma).
• C: N m is the unit for work or energy (Joule).
• D: N/m is the unit for spring constant (Hooke's law, F = kx).

Final answer: A