MotionGenesis: F=ma Software, textbooks, training, consulting.      Units and conversion factors
To convert from inches to cm, enter
inchToCm = ConvertUnits( inches, cm )

To convert   3 slug ft2   to units of   kg cm2,   enter either of:

conversionFactor = 3*ConvertUnits( slug*ft^2, kg*cm^2 )
conversionFactor = ConvertUnits( 3 slug*ft^2, kg*cm^2 )

To list the large-number of available units, type

  The default unit system is   kilograms, meter, second.
To change the default unit system, type (for example)
SetUnitSystem( gram, cm, hour )

UnitSystem affects conversion factors for:
Input Output ODE Solve

Example:   Choose a gear ratio to move a 10 degree hill.
  • You and your bike have a combined mass of 80 kg.
  • The bike's wheels have radii of 33 cm   (diameter of 26 inches).
  • You can produce 1/8 horsepower   (8 strong people equal one horse).
  • Determine the gear ratio   (pedal angular speed / wheel angular speed).
    so you can pedal at your prefer rate of 1.5 rotations per second.
  • Recalculate the gear ratio for hills of 20 degrees and 30 degrees.
MotionGenesis commands     MotionGenesis responses
  MotionGenesis: MGBikeRiderUphillAnimated.gif with Working Model.