Negative outcome?

Question

import static java.lang.Math.*;
public class catapult
    private double acceleration = 9.8;
     * Default constructor for objects of type catapult
    catapult()
     * Accessor Method to calculate the distance in meters
     * @param velocity of object (launch speed)
     * @param the launch angle
     * @param the acceleration due to gravity
     * @return the distance an object will be launched
    public double calcR(double speed, double angle)
        return (Math.pow(speed, 2) * sin(2 * angle)) / acceleration;
}this is class one
public class catapultTester
    public static void main(String[] args)
        //variable declaration
        double speed1 = 20;
        double speed2 = 25;
        double speed3 = 30;
        double speed4 = 35;
        double speed5 = 40;
        double speed6 = 45;
        double speed7 = 50;
        double angle1 = 25;
        double angle2 = 30;
        double angle3 = 35;
        double angle4 = 40;
        double angle5 = 45;
        double angle6 = 50;
        double MPH20, MPH201, MPH202, MPH203, MPH204, MPH205;
        double MPH25, MPH251, MPH252, MPH253, MPH254, MPH255;
        double MPH30, MPH301, MPH302, MPH303, MPH304, MPH305;
        double MPH35, MPH351, MPH352, MPH353, MPH354, MPH355;
        double MPH40, MPH401, MPH402, MPH403, MPH404, MPH405;
        double MPH45, MPH451, MPH452, MPH453, MPH454, MPH455;
        double MPH50, MPH501, MPH502, MPH503, MPH504, MPH505;
        //create object
        catapult fire = new catapult();
        MPH20 = fire.calcR(speed1, angle1);
        MPH201 = fire.calcR(speed1, angle2);
        MPH202 = fire.calcR(speed1, angle3);
        MPH203 = fire.calcR(speed1, angle4);
        MPH204 = fire.calcR(speed1, angle5);
        MPH205 = fire.calcR(speed1, angle6);
        System.out.println(MPH201);
}this is class 2. When I print the outcome, it's negative. why is it doing that?

Answer 1

Yep thats how i would have done it :). Really manually how you convert degrees to radians if you wanted to know is take the (Degree*pi)/180
Oh and here is the java api... the best reference for things java.
http://java.sun.com/j2se/1.5.0/docs/api/
on the left you click the class you wanna look up like Math and you can see the individual methods it has. Click a method for its advanced documentation.
Edited by: javed.b.ahamed on Feb 16, 2008 11:36 AM