Question 1

Which of the following conditions must be satisfied for a system to be in true static equilibrium?

Accepted Answer

Both the sum of the forces and the sum of the torques must be zero.

Question 2

The moment of inertia of a rigid body about an axis is given by which of the following equations?

Accepted Answer

$$I = \sum m_i r_i^2$

Question 3

Which theorem allows you to calculate the moment of inertia about any axis parallel to one passing through the center of mass?

Accepted Answer

Parallel Axis Theorem

Question 4

A ladder leans against a frictionless wall. Which force is responsible for preventing the ladder from slipping at the base?

Accepted Answer

Frictional force from the ground

Question 5

If a system is perturbed by wind or an earthquake, what is the desired architectural response according to the principles of static equilibrium?

Accepted Answer

The system should return to equilibrium.

Question 6

The torque produced by a force $$F$$ acting at a distance $$r$$ from the axis of rotation is given by:

Accepted Answer

$$	au = r 	imes F$$

Question 7

In a bicep curl problem, why is it useful to take torques about the elbow joint?

Accepted Answer

It eliminates the torque due to the elbow joint forces.

Question 8

Which equation correctly represents the force exerted by a spring according to Hooke's Law?

Accepted Answer

$$F = -kx$$

Question 9

A ball is held in the hand with the arm horizontal. If the mass of the ball is $$m$$ and the distance from the elbow to the ball is $$d$$, what is the torque due to the ball about the elbow?

Accepted Answer

$$	au = m g d$$

Question 10

In a static equilibrium problem involving a knee joint, why is it advantageous to take torques about the point where the knee acts?

Accepted Answer

It eliminates the torque due to the knee forces.

Question 11

Which of the following is true about the net torque in static equilibrium?

Accepted Answer

Net torque must be zero about any axis.

Question 12

A pulley system rotates with a net torque. According to Newton's Law of Rotation, which equation describes its angular acceleration $$\alpha$$?

Accepted Answer

$$	au_{net} = I \alpha$$

Question 13

Which of the following best describes the role of friction in rolling motion?

Accepted Answer

Friction provides the torque needed for rolling without slipping.

Question 14

If the sum of the forces in the y-direction for a static system is zero, which equation represents this condition?

Accepted Answer

$$\sum F_y = 0$$

Question 15

A building is designed to return to equilibrium after a disturbance. What type of equilibrium does this represent?

Accepted Answer

Stable equilibrium

Static Equilibrium and Rotational Dynamics: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards