Force Calculator (Newton's Second Law)

Newton’s Second Law of Motion:

Force = Mass × Acceleration

F = m × a

Rearranged:

Mass = Force / Acceleration → m = F / a

Acceleration = Force / Mass → a = F / m

SI Units:

• Force is measured in Newtons (N) — 1 N = 1 kg·m/s²
• Mass is measured in kilograms (kg)
• Acceleration is measured in meters per second squared (m/s²)

Imperial Units:

• Force is measured in pound-force (lbf) — 1 lbf = 1 slug·ft/s²
• Mass is measured in slugs — 1 slug ≈ 14.594 kg
• Acceleration is measured in feet per second squared (ft/s²)

SI Examples:

• A 1 kg object at Earth’s gravity: F = 1 × 9.81 = 9.81 N
• A 2,000 kg car accelerating at 3 m/s²: F = 2000 × 3 = 6,000 N

Imperial Examples:

• A 1 slug object at Earth’s gravity: F = 1 × 32.17 = 32.17 lbf
• A 100 slug vehicle accelerating at 10 ft/s²: F = 100 × 10 = 1,000 lbf

Gravity constants:

• Earth: 9.81 m/s² (SI) / 32.17 ft/s² (imperial)
• Moon: 1.62 m/s² (SI) / 5.32 ft/s² (imperial)