# Making the bike pedal

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• 03-22-2011, 06:53 AM
jinglylime
Making the bike pedal
hi, im trying to make a bike move by using the pedal() method, the method will move the bike forward a distance of half the circumference of a wheel. ive tried creating the pedal() method however when the method is invoke the position of the bike is still the same. please help me. thanks.

Code:

```public class Wheel {     private double position;     private double radius;     public Wheel()     {         position = 0.0;         radius = 50.0;     }     public void setRadius(double newRadius)     {         radius = newRadius;     }         public void setPosition(double newPosition)     {         position = newPosition;     }     public void rollForward(double distance)     {         position = position + distance;     }     public double getPosition()     {         return position;     }         public double getRadius()     {         return radius;     }         public double getCircumference()     {         double circumference;         circumference = 2*radius*Math.PI;         return circumference;     }     }```
Code:

```public class Bike {     private Wheel frontWheel;     private Wheel backWheel;     public Bike()     {                 frontWheel = new Wheel();         backWheel = new Wheel();                 frontWheel.setPosition(50);         backWheel.setPosition(-50);     }         public double getPosition()     {         double position;         position = (frontWheel.getPosition() + backWheel.getPosition())/2;         return position;             }     public double pedal() // here's my problem     {                 double position;         position = getPosition() + frontWheel.getCircumference()/2;         return position;     } }```