Projects‎ > ‎(1) Discrepant Events‎ > ‎

## Author

Laura Silverman, 7th grade Science, Mulholland Middle School

## Principle(s) Illustrated

1.  Momentum transfers to other objects and is cumulative.
2.  Energy cannot be created or destroyed, it can only be moved around.
3. E = MGH

## Standards

8.2 Forces:  Unbalanced forces cause changes in velocity.
a.  Students know a force has both direction and magnitude.
b.  Students know when an object is subject to two or more forces at once, the result is
the cumulative effect of all the forces.
e.  Students know that when the forces on an object are unbalanced, the object will change its velocity (that is, it will speed up, slow down, or change direction).
f.  Students know the greater the mass of an object, the more force is needed to achieve the same rate of change in motion.

## Questioning Script

Prior knowledge & experience:

Students know that basketballs and tennis balls will bounce fairly high.

Root question:

How will the tennis ball bounce when placed on top of the basketball and bounced together.

Target response:

Students will be shocked at how much higher the tennis ball will bounce than could ever have been expected (if you have never seen this before).

Common Misconceptions:

That a larger object will tranfser a proportionally larger amount of momentum to a relatively smaller object and can cause a great increase in distance travelled.

## References

Science-Projects "The Basketball and Tennisball", retreived September 7, 2011 at http://www.science-projects.com/Drop/DropBalls.htm

Exploratorium "Baseketball", retreived September 7, 2011 at http://www.exploratorium.edu/baseball/baseketball.html