1. Motion http://commons.wikimedia.org/wiki/File:Soccer_kick.jpg

2. A Tropism Plants in Motion Plants move. What do we call it when
plants move by growing in a certain
direction?
A Tropism

3. Key Understandings Motion is a change in position.
A force is a push or pull that can change motion.
Forces cause changes in position, speed, and direction.

4. Unbalanced Forces
In order for a force to move an object, there must be unbalanced forces.
Like tug of war…the winners are pulling the other team with more force; therefore, the pulling forces are unbalanced.

5. How can unbalanced forces affect objects?
Unbalanced forces can change the position, speed, or direction of an object.
Resistance forces (friction or wind) that oppose motion can slow down an object.
A force in the same direction can cause an object to speed up.
A force from a different direction can change the object’s direction.

6. Balanced Forces
If we have unbalanced forces, then there must be balanced forces.
When forces are balanced, an object’s motion will be constant. It will not change speed or direction.