Physics 10-10
unstable equilibrium
An object balanced so that any displacement lowers its center of gravity is in unstable equilibrium.
neutral equilibrium
An object in this state's CG is neither raised nor lowered with displacement.
True or False: An object will topple if its CG is above the area of support.
False
True or False: For everyday objects, the center of gravity and the center if mass are different.
False
True or false: An object is in unstable equilibrium when any displacement raises its CG.
False
Where is the CG of a donut?
In the hole
What is suggested by a star that wobbles off center?
It has a planetary system
Why is the CG of a baseball bat not at its midpoint?
It has more mass toward the thicker end
What part of an object follows a smooth path when the object is made to spin through the air?
It's CG
Is the gravitational energy more, less, or unchanged when the CG of an object is raised?
More
Can a rigid object have more than one CG?
No
How can the CG of an irregularity shaped object be determined?
Suspend from 2 or more points; see where the lines intersect.
Why doesn't the leaning tower of pisa topple?
The CG is above it's support base.
Center of gravity
The CG of an object is the point at the center of its weight distribution.
Center of mass
The center of gravity is often call center of mass, which is the average position of all the particles of mass that make up an object.
Why do you spread your feet farther apart when standing in a bumpy bus?
To increase the support base for stability
To resist being toppled, why does a wrestler stand with feet wide apart?
To increase the support base.
To resist being toppled, why does a wrestler stand with knees bent?
To lower the CG.
When you carry a heavy load with one arm, why do you hold your free arm out horizontally?
To shift the CG of your body away from the load.
True or False: The CG of an object is the point at the the center its weight of distribution
True
True or false: When an object is thrown through the air, its CG follows a smooth parabolic path.
True
How far can an object be tripped before it topples over?
Until the CG extends beyond the support base.
stable equilibrium
We say an object that is balanced so that any displacement raises its center of gravity is in stable equilibrium.
Why can't you successfully bend over and touch your toes when you stand with heels against the wall?
Your CG will extend beyond your support base.
