Scaled - Measured Vector Method

To use this method you will need a ruler and a protractor. (The protractor can be disregarded if you are working with a time lapse photograph of the collision.)

This animation shows the collision of two asteroids and an analysis of the total momentum before and after the collision. Since the two total momenta are identical we can say that momenum is conserved.

Calculate the momentum (m·v) of each object.
Choose a scale that is appropriate for the size of the momentum vectors.
(example: If the largest of the vectors is 2400kgm/s then a scale of 1cm = 1000kgm/s would work well.)
Using the protractor and ruler, draw each of the scaled vectors for the momenta before the interaction (collision, explosion, attraction, repulsion)
- Arrange them head to tail or complete the parallelogram.
- Draw the resultant vector (represents the total momentum before the interaction).
Using the protractor and ruler, draw each of the scaled vectors for the momenta after the interaction (collision, explosion, attraction, repulsion)
- Arrange them head to tail or complete the parallelogram.
- Draw the resultant vector (represents the total momentum after the interaction).
Compare the magnitude and direction of the total momentum vectors before and after the collision. If they are identical then momentum is conserved.