Engineering Mechanics Lecture Notes Practice Flashcards

Vocabulary practice flashcards covering core concepts of Engineering Mechanics including linear and angular motion, friction, equilibrium, moments, and work/energy.

Density ($\rho$)

The ratio of mass to volume, calculated using the formula $\rho = \frac{m}{v}$ where $m$ is mass and $v$ is volume.

Resultant Force

The single equivalent force that represents the combined magnitude and direction of all individual forces acting on a body.

Equilibrium

The state of a system where the resultant of all forces and the resultant of all moments are zero, meaning the body is at rest or in constant motion.

Normal Reaction

The perpendicular force exerted by a surface on an object to support its weight or counteract applied forces, often represented as $NR$.

Fulcrum

The fixed pivot point about which a lever or bell crank is rotated; also referred to as a pivot.

Moment

The turning effect of a force about a specific point or pivot, calculated as the product of the force and its perpendicular distance from the point.

Uniformly Distributed Load (UDL)

A load that is spread evenly across a structural element (like a beam), usually measured in force per unit length such as $N/m$ or $kN/m$.

Coefficient of Static Friction ($\mu_s$)

The ratio of the maximum friction force to the normal force between two surfaces when they are at the point of impending motion.

Friction Angle

The angle related to the coefficient of friction; for example, the angle at which an object is calculated to move down an inclined plane.

Centre of Gravity

The point in a body (or composite body) where the entire weight can be considered to act; it must often be solved using tabular calculations for X and Y coordinates.

Retardation

The uniform reduction in velocity over time, also known as negative acceleration; measured in units like $km/h/s$ or $m/s^2$.

Angular Velocity ($\omega$)

The rate of change of angular displacement of an object moving in a circular path, expressed in radians per second ($rad/s$).

Rotational Frequency

The number of complete revolutions an object makes per unit of time, typically measured in revolutions per minute ($rpm$).

Spring Stiffness ($k$)

The property of a spring defined by the ratio of the force applied to the resulting displacement, measured in units like $N/m$ or $kN/m$.

Tractive Resistance

A constant force that opposes the motion of a vehicle, which must be overcome by the work or power developed by the engine.

Gearing Efficiency

The percentage of engine power that effectively reaches the wheels or output shaft, accounting for losses in the mechanical system.