Exam 12: Equilibrium and Elasticity

A uniform plank XY is supported by two equal 120-N forces at X and Y, as shown.The support at X is then moved to Z (half-way to the plank center).The supporting forces at Y and Z are then:

A cylinder placed so it can roll on a horizontal table top, with its center of gravity above its geometrical center, is:

A force of 5000 N is applied outwardly to each end of a 5.0-m long rod with a radius of 34.0 mm and a Young's modulus of 125 * 10⁸ N/m².The elongation of the rod is:

Which of the following is in static equilibrium?

The bulk modulus is a proportionality constant that relates the pressure acting on an object to:

A massless meter stick on a horizontal frictionless table top is pivoted at the 80-cm mark.A force is applied perpendicularly to the end of the stick at 0 cm, as shown.A second force (not shown)is applied perpendicularly to the stick at the 100-cm end of the stick.The forces are in the plane of the table top.If the stick does not move, the force exerted by the pivot on the stick:

A cube with 2.0-cm sides is made of material with a bulk modulus of 4.7 * 10⁵ N/m².When it is subjected to a pressure of 2.0 * 10⁵ Pa the length in cm of its any of its any of its sides is:

A picture can be hung on a wall in three different ways, as shown.The tension in the string is:

A uniform rod AB is 1.2 m long and weighs 16 N.It is suspended by strings AC and BD as shown.A block P weighing 96 N is attached at E, 0.30 m from A.The magnitude of the tension force in the string BD is:

A window washer attempts to lean a ladder against a frictionless wall.He finds that the ladder slips on the ground when it is placed at an angle of less than 75 $\degree$ to the ground but remains in place when the angle is greater than 75 $\degree$ .The coefficient of static friction between the ladder and the ground:

A picture is to be hung from the ceiling by means of two wires.Order the following arrangements of the wires according to the tension in wire B, from least to greatest.

An 800-N man stands halfway up a 5.0 m ladder of negligible weight.The base of the ladder is 3.0 m from the wall as shown.Assuming that the wall-ladder contact is frictionless, the wall pushes against the ladder with a force of:

A 160-N child sits on a light swing and is pulled back and held with a horizontal force of 100 N.The magnitude of the tension force of each of the two supporting ropes is:

If you sit on an ordinary 4-legged chair, which of the following is true?

The location of which of the following points within an object might depend on the orientation of the object?

Strain can be measured in:

The pull P is just sufficient to keep the 14-N block and the weightless pulleys in equilibrium as shown.The tension T in the upper cable is:

To shear a cube-shaped object, forces of equal magnitude and opposite directions might be applied:

The ideal mechanical advantage (i.e.the ratio of the weight W to the pull P for equilibrium)of the combination of pulleys shown is:

Which of the following is NOT in equilibrium?