# Center of Gravity.

## Presentation on theme: "Center of Gravity."— Presentation transcript:

Center of Gravity

Challenge: Leg Lift

Stable vs. Unstable

Stable Structures The forces of gravity acts on all parts of the structure All parts are evenly distributed around the center of gravity = the structure is stable

Unstable Structures A structure may collapse if the external forces causes the structure to become unbalanced Also known as an “unbalanced” structure

Firm Foundation The foundation must be stable.
If not, compressive forces may cause structure to tip and become unstable. Soil type and formations critically important in building planning

Build on FIRM FOUNDATION!!!
Leaning Tower of Pisa Build on FIRM FOUNDATION!!!

Class Challenge: Super Glue Chair

Center of Gravity

What is center of gravity?
The center of gravity is the specific point where all of the mass of the structure is evenly distributed around

Mass vs. Weight Mass Amount of matter in an object Weight
Force of gravity felt on that object

What is “equilibrium” A state in which opposing forces or influences are balanced in a “system” A state of physical balance

What is a “system” A structure made up of parts all related to one another

Challenge: The Impossible Leap

Ways to Increase Stability
Lower the center of gravity = widening structure Increase speed (bike)

Ruler Experiment

Experiment: Spoon & Fork
Steps Hand in your graphic organizer. In partners of 2, get a spoon, fork, toothpick and a beaker Put fork and spoon together Add toothpick Find center of gravity by balancing on table *Bonus* - break off toothpick where center of gravity is Draw your “system” and label. Include center of gravity, equilibrium line. Explain why the “system” is balanced (ie: why is it balancing?)