mathjsunits07.js

mathjsunits07.js

function gravity()
{
    // calculate the weight of a person on massMars

    // the values needed as math.unit objects
    const massPerson  = math.unit(75, 'kg');
    const massMars  = math.unit(6.4171e23, 'kg');
    const radiusMars = math.unit(3389500, 'm');

    // implement formula in 4 stages using math.js methods
    const numerator = math.multiply(massPerson, massMars);
    const denominator = math.pow(radiusMars, 2);
    const quotient = math.divide(numerator, denominator);
    const newtons = math.multiply(math.gravitationConstant, quotient);

    // convert Newtons to kg
    const weightOnMars = math.unit(math.divide(newtons.toNumber(), 9.80665), 'kg');

    output(`massPerson: ${massPerson}`);
    output(`massMars: ${massMars.to('kg')}`);
    output(`radiusMars: ${radiusMars.to('km')}`);
    output(`Newtons: ${newtons}`);
    output(`weightOnMars: ${weightOnMars.to('kg')}`);
}