Increase in horsepower Calculation based on 0-60 times

horsepowerIncrease

#include <stdlib.h>
#include<iostream>
using namespace std;


/**
 * Estimates the increase in horsepower of a car based on weight and a change in 0 to 60 times.
 * 
 * @author Jimmy Goodsell
 */
int main(){
    double w,t,e, hptheo, hptheo2, hpreal, hpreal2, eff, t2;
    cout << "Please insert car weight (in lbs), 0-60 time (seconds), and horsepower" << endl;
    cin >> w >> t >> hpreal;
    w*=0.45359237;
    e = .5*w*26.8224*26.8224;
    hptheo = (e/t)/745.699872;
    eff = (hptheo/hpreal);
    cout << "The efficiency is: " << eff<< endl << "Now enter the new 0-60 time (in seconds)" << endl;
    cin >> t2;
    hptheo2 = (e/t2)/745.699872;
    hpreal2 = hptheo2/eff;

    cout << "The new horsepower of the car is: " << hpreal2 << " horsepower, a gain of " << hpreal2-hpreal << " horsepower" << endl;

    return 0;
    
}