Vector

To draw a vector, select the Vector tool ; then click in the applet window and draw with the mouse. You can change the vector by dragging either its tail or its tip. You can move the vector without changing it by clicking it somewhere near its middle and dragging it.

To draw a second vector, repeat the procedure, beginning with the selection of the Vector tool. The applet will not allow you to draw more than two vectors.

Dotted Line

When constructing the sum of two vectors via the parallelogram method, you will need to construct the parallelogram spanned by the two vectors. The Dotted-Line tool lets you draw dotted lines for this purpose. To draw a line, select the Dotted-Line tool ; then click in the applet window and draw with the mouse.

You can change a dotted line by dragging either its tail or its tip. You can move the line without changing it by clicking it somewhere near its middle and dragging it.

The Dotted-Line tool does not become active until two vectors have been drawn.

Resultant

The Resultant tool becomes active only after two vectors have been drawn. This tool lets you draw a vector anywhere on the screen and works just like the Vector tool. Use this tool to draw arrow representing the sum (resultant) of the two vectors drawn earlier, after either aligning them tip-to-tail or constructing the parallelogram spanned by the two vectors. The resultant vector will be drawn in blue.

You can change your resultant by dragging either its tip or its tail end. You can move the resultant without changing it by clicking near the middle of the arrow and dragging it.

Reset

Clears the applet window and gets the applet ready so that you can draw another pair of vectors.

Answer

The Answer button becomes active only after you have drawn a resultant. When you click the Answer button, the applet will show the correct resultant in green. For better comparison of the two resultants, your blue one and the green one provided by the applet, you can move either vector by clicking on it and dragging.