Pre-lesson Quiz: Stability and Types of Equilibrium

State the principle of moments.

• When an object is in equilibrium, the sum of the total clockwise moment is equal to the sum of the total anti-clockwise moment about the centre of gravity.

• When ab object is in equilibrium, the sum of the moments is equals.

• When a system is in equilibrium, the sum of the total clockwise moment is equal to the sum of the total anti-clockwise moment about the centre of gravity.

• When an object is in equilibrium, the sum of the total clockwise moment is equal to the sum of the total anti-clockwise moment about the same pivot.

What is the anticlockwise moment acting on this crane?

• 80,000Nm

• 100,000Nm

• 120,000Nm

• 140,000Nm

For a uniform rod, the centre of gravity is present at

• centre of the rod

• the ends of the rod

• varies from material to material

• the cross-sectional area

Where is the centre of gravity of a uniform ring situated ?

• 
• 
• 
• 

What is one way you might increase the stability of an object?

• Lower the centre of gravity

• Raise the centre of gravity

• Increase the height

• Shorten the base

The diagrams show four solid cones. The centre of mass of each cone is marked by a point labelled M.

• A

• B

• C

• D

Using the center of gravity of an object, how do we tell when the object has reached its tipping point?

• Right before the center of gravity passes past the base of the object

• Right after the center of gravity passes past the base of the object

• When the center of gravity moves upwards

• When the center of gravity stays at the same height