Science Sportacular - Liberty Science Center

I. Activities Exploring Gravity and Weight
Center of Gravity: Lean on Me
Materials:
Students of similar height
Male and female students
A wall
All objects have a point where they are held in balance by the force of gravity. This
balancing point is called the center of gravity because it is the place where the whole weight of
the object seems to center.
Activity #1
Procedure:
1. Pair students of similar heights.
2. Have everyone point to where they think their center of gravity is.
(*In most people standing up, their center of gravity is located about one (1) inch below the
navel.)
3. Have the students who are similar in height stand back to back shoulder to shoulder,
and heel to heel.
4. Next have the students bend over and attempt to touch their toes while keeping their
backsides together.
*This is an impossible task as the student’s center of gravity moves forward and makes their
back to back stance unstable
Activity #2
*Only females will be able to accomplish this task since their center of gravity is just a little lower
than that of males. When a male bends over in this stance, he places his center of gravity
beyond his toes. A female maintains her center of gravity above her feet and can straighten up
with little difficulty. This does not always work with young children.
Continued…