Bennett Mechanical Test Structures and Center of Gravity 4

Question 1

A ladder leans against a wall. To reduce the chance it slides out, the base should be?

Accepted Answer

Closer to the wall (steeper)

Answer

A steeper ladder reduces the horizontal force at the base, lowering the slide tendency.

Question 2

Two columns support a uniform beam carrying a load at its exact center. How is the load shared?

Accepted Answer

Equally between the two columns

Answer

A centered load on a symmetric beam splits equally to both supports.

Question 3

A cone resting on its point is in what kind of equilibrium?

Accepted Answer

Unstable

Answer

Balanced on its tip, any small tilt moves the center of gravity past the contact point, so it is unstable.

Question 4

A ball rolling on a flat level surface is in what kind of equilibrium?

Accepted Answer

Neutral

Answer

On a flat surface the ball's center of gravity stays the same height when moved, which is neutral equilibrium.

Question 5

A crane lifts a load. To avoid tipping, a heavy counterweight is placed where?

Accepted Answer

On the opposite side of the pivot from the load

Answer

A counterweight on the opposite side balances the load's moment and keeps the crane from tipping.

Bennett Mechanical Test Practice Test