Reduced Mass Calculator

Calculate the reduced mass of a two-body system for simplified physics problems

Calculate Reduced Mass

Mass of the first object in the two-body system

Mass of the second object in the two-body system

Reduced Mass Results

0
Kilograms (kg)
μ
Reduced Mass Symbol

Formula used: μ = (m₁ × m₂) / (m₁ + m₂)

Input masses: m₁ = 0 kg, m₂ = 0 kg

Properties: μ ≤ min(m₁, m₂) and μ ≤ (m₁ + m₂)/2

Example Calculations

Earth-Sun System

Earth mass (m₁): 5.972 × 10²⁴ kg

Sun mass (m₂): 1.989 × 10³⁰ kg

Calculation: μ = (5.972×10²⁴ × 1.989×10³⁰) / (5.972×10²⁴ + 1.989×10³⁰)

Result: μ ≈ 5.972 × 10²⁴ kg ≈ 1 Earth mass

Hydrogen Atom (Proton-Electron)

Proton mass: 1.673 × 10⁻²⁷ kg

Electron mass: 9.109 × 10⁻³¹ kg

Reduced mass: μ ≈ 9.105 × 10⁻³¹ kg ≈ 0.9995 mₑ

Physics Applications

1

Orbital Mechanics

Planetary and satellite orbits

2

Atomic Physics

Hydrogen atom and molecular systems

3

Binary Stars

Double star systems and dynamics

4

Quantum Mechanics

Two-particle quantum systems

Key Properties

Always smaller than both individual masses

Symmetric: μ(m₁,m₂) = μ(m₂,m₁)

Approaches smaller mass when masses differ greatly

Equals m/2 when both masses are equal

Understanding Reduced Mass

What is Reduced Mass?

Reduced mass is a physical quantity that allows us to convert a two-body problem into an equivalent one-body problem. Instead of tracking two objects affecting each other, we can analyze the relative motion using a single effective mass.

Why Use Reduced Mass?

  • Simplifies complex two-body dynamics
  • Enables analytical solutions for orbital problems
  • Essential for quantum mechanical calculations
  • Separates center-of-mass and relative motion

Mathematical Formula

μ = (m₁ × m₂) / (m₁ + m₂)

  • μ (mu): Reduced mass
  • m₁: Mass of first object
  • m₂: Mass of second object

Alternative form: 1/μ = 1/m₁ + 1/m₂

Physical Interpretation

The reduced mass represents the effective mass that would produce the same relative motion between two objects as if one object were fixed and the other moved with mass μ.