1.3 Mass and Weight

Weight, Gravity, & Planets Lab

Simulate gravity between planetary bodies. Tweak planet masses and their distance to observe attractive force and verify the gravitational inverse-square law.

Virtual Viewport
PlanetMoonF_grav = 18.26 ×10²⁰ N

Active Sliders

m₁Mass of Planet6.00×10²⁴ kg
110

Mass of primary planet (e.g. Earth = 6.0).

m₂Mass of Satellite7.30×10²² kg
110

Mass of secondary body (e.g. Moon = 7.3).

rDistance apart4.00×10⁵ km
210

Center-to-center separation distance.

Syllabus Objectives

  • Define gravitational force and field strength (g)
  • State the relationship between weight, mass, and gravitational field strength
  • Verify the inverse-square dependency of distance on gravitational force.

Mathematical Equations

Weight Equation
W = m g
Newton's Gravity Law
F = G m1 m2r²

Inquiry Guide Sheet

1

Set distance (r) to 4. Note the force. Double the distance to 8. Observe how force shrinks to 1/4.

2

Triple the distance and confirm that force reduces to 1/9.

3

Vary mass 1 and mass 2. Observe the direct linear relationship with force.