// MPH = ((HP / Weight)^.333) * 234
var horsepower1_calc = function() {
    var mph,
    weight1,
    horsepower1;
    mph = Number(document.speed.MPH.value);
    weight1 = Number(document.speed.Weight1.value);
    horsepower1 = Math.pow((mph / 282), 2.49793) * weight1;
    document.speed.Horsepower1.value = Math.round(horsepower1);
    return horsepower1;
};
// HP = (Weight / ((ET/5.825)^3))
var horsepower2_calc = function() {
    var et,
    weight2,
    horsepower2;
    et = Number(document.time.ET.value);
    weight2 = Number(document.time.Weight2.value);
    horsepower2 = weight2 / Math.pow((et / 5.825), 3);
    document.time.Horsepower2.value = Math.round(horsepower2);
    return horsepower2;
};