Addition of forces

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Vector sum of forces:

1. Translate and join the arrows together such that the tip of one proceeds the tail of another.

2. The order of "tip-tail joining" does not matter.

3. Draw a new arrow from the tail of the first arrow to the tip of the last one, this is the resultant force.

Although the order of joining is different, the resultant (hollow arrow) is the same.

In this applet, up to 4 forces can be created in a random manner. The tip of each force can be dragged to move and hence the magnitude and direction of that force are changed accordingly.

Unless the forces are balanced, a black hollow arrow appears and blinks a few times after the completion of a "tip-tail joining". This hollow arrow is the resultant force, which represents physically all the original forces.

The order of "tip-tail" joining is random and redecided each time when the button "Vector sum" is pressed. You are advised to repeat "Vector sum" and then "Restore" several times to see how the same resulatnt be obtained despite the order is different.

The "F" in Newton's second law of motion, F = ma, stands for the resulatnt of the forces acting on an object of mass m. The acceleration produced is thus in the same direction of the resultant force. When the button "Motion' is pressed, the yellow object will go and accelerate under the influence of the resultant force.