Physics Force Calculator — F=ma, Weight & Momentum
Calculate force, mass, acceleration, weight, and momentum using Newton's Laws. Select equation, enter known values, get results with step-by-step explanation.
F = m × a
—
Result
—
Units
—
Equivalent
Step-by-Step
Gravity on Different Bodies
Earth9.81 m/s²
Moon1.62 m/s² (1/6 of Earth)
Mars3.72 m/s²
Jupiter24.79 m/s²
Sun274 m/s²
Frequently Asked Questions
What is Newton's Second Law?
Newton's Second Law states F = ma: Force equals mass times acceleration. It means a net force acting on a mass produces acceleration proportional to the force and inversely proportional to the mass.
What is the difference between mass and weight?
Mass (kg) is the amount of matter in an object — it is constant everywhere. Weight (N) is the gravitational force on an object: W = mg. On Earth, g ≈ 9.81 m/s², so a 10 kg object weighs 98.1 N. On the Moon (g ≈ 1.62 m/s²), the same 10 kg object weighs only 16.2 N.
What is momentum?
Momentum (p) = mass × velocity: p = mv. It is a vector quantity with units kg·m/s. Newton's second law can be expressed as: Force = rate of change of momentum.
What are the SI units of force?
The SI unit of force is the Newton (N). 1 N = 1 kg·m/s². Other units: 1 kN = 1000 N, 1 lb-force ≈ 4.448 N. Pressure adds area: 1 Pa = 1 N/m².
What is friction force?
Friction force Ff = μN, where μ is the coefficient of friction and N is the normal force. Static friction prevents motion (μs), while kinetic friction acts during motion (μk < μs). This calculator focuses on F=ma, W=mg, and p=mv.