Preliminary Engineering Studies Flashcards

Vocabulary flashcards generated from Preliminary Engineering Studies notes covering Engineering Fundamentals, Engineered Products, Braking Systems, and Biomedical Engineering.

Newton's First Law of Motion

A body will remain at rest or at constant velocity unless acted upon by an unbalanced external force.

Newton's Second Law of Motion

A body acted upon by an external unbalanced force will accelerate in proportion to the magnitude of this force in the direction in which it acts ($F = ma$).

Newton's Third Law of Motion

To every action there is an equal and opposite reaction.

Mass

The amount of matter that a body contains, with the SI unit being the kilogram ($kg$).

Force

A push or pull on a body measured in Newtons ($N$).

Weight

A force created by gravity representing the effect that the Earth's gravitational force has on a body ($W = mg$).

Scalar Quantities

Quantities that are defined by their magnitude only, such as distance, time, and mass.

Vector Quantities

Quantities defined by both their magnitude and direction, such as displacement, force, and velocity.

Lever

The simplest machine using force acting over a distance to magnify effort, providing mechanical advantage through leverage.

Thermoplastics

Also known as thermosoftening polymers, these possess covalent bonds and weak secondary bonds between chains, allowing them to be resoftened and reformed by heating.

Thermosets

Polymers that cannot be resoftened or reshaped by heating once formed.

Hardness

The ability of a material to resist scratching, abrasion, or indentation.

Malleability

The ability of a material to be hammered and rolled into thin sheets.

Ductility

The ability of a material to be drawn out into thin wire.

Body Centred Cubic (BCC)

One of the three most important regular crystal structures into which atoms arrange as a material solidifies.

Face Centred Cubic (FCC)

A major regular crystal structure formed by solidifying materials, characterized by face-centered atomic arrangements.

Hexagonal Close Packed (HCP)

One of the three primary regular crystal structures formed during material solidification.

Polymorphism

Also known as allotropy, the ability of a single substance to exist in multiple forms or crystal structures.

Amorphous

Non-crystalline materials without form or atomic order, such as liquids, gases, and glass.

Brass

An alloy of copper and zinc containing up to $40\%$ zinc, offering corrosion resistance, hardness, and wear resistance.

Bronze

An alloy of copper and tin that can be pressed, sintered, and impregnated with lubricants like oil, graphite, or PTFE.

Couple

Two parallel, co-planar forces of the same magnitude and direction but opposite sense, that produce or tend to produce rotation but not translation.

Moment of a Force

The rotational effect caused by a force, calculated by multiplying the magnitude of the force by the perpendicular distance from the pivot point ($M = Fd$).

Equilibrant

The force that balances all other combined forces in a system to achieve equilibrium.

Principle of Transmissibility

The principle stating that a force may be relocated at any position along its line of action provided it retains the same magnitude and direction.

Work Hardening

Also called cold working, a process where a material is worked at a temperature below its recrystallization temperature, causing atoms to slip along shear planes to toughen and shape it.

Annealing

A heat process where metal is heated to a specific temperature ($900^\circ\text{C}$) and allowed to cool slowly to soften it for easier cutting and shaping.

Quenching

A heat-treating process involving the rapid cooling of a workpiece to obtain specific material properties such as increased hardness.

Current

The quantity of electrons flowing through a system per second, measured in amperes ($A$).

Voltage

Also known as electrical potential difference, it is the potential difference between the point where electrons enter a system and exit it, measured in volts ($V$).

Magnetic Induction

The process by which a substance, such as iron or steel, becomes magnetized by a magnetic field radiating from a magnet's poles.

Anti-Lock Braking System (ABS)

An automobile safety system introduced in 1929 that allows wheels to maintain tractive contact with the road while braking, preventing wheel lockup and skidding.

Regenerative Braking

An energy recovery mechanism that slows a vehicle by converting kinetic energy into a form that can be used immediately or stored as electrical energy.

Stress

The relationship between an applied load and a material's cross-sectional area ($\sigma = \frac{P}{A}$), measured in Pascals ($Pa$) or Mega Pascals ($MPa$).

Strain

The proportional change in length of a material under an axial load.

Hooke's Law

The law stating that stress is directly proportional to strain up to a material's elastic limit.

Yield Point

The point during material testing where there is a marked increase in extension without an increase in load.

Pascal's Principle

Principle stating that pressure applied to a confined liquid is transmitted equally throughout the liquid ($P = \frac{F}{A}$).

Austenite

A constituent structure of steel formed when heated to $1000^\circ\text{C}$, possessing a Face Centred Cubic (FCC) crystal structure.

Ferrite

A soft and ductile form of pure iron with a Body Centred Cubic structure, containing a maximum of $0.025\%$ dissolved carbon.

Cementite

A hard, brittle iron carbide present in cast iron and most steels.

Pearlite

A finely laminated mixture of ferrite and cementite present in cast iron and steel formed by the cooling of austenite.

Eutectoid Steel

Any steel with a carbon composition of exactly $0.83\%$ carbon.

First Order Lever

A lever system where the load and the effort are placed on either side of the pivot point, such as in a crowbar or surgical retractors.

Second Order Lever

A lever system where the load is positioned between the pivot point and the effort, such as in a wheelbarrow or brake pedal.

Third Order Lever

A lever system where the effort is placed between the load and the pivot point, resulting in an effort that is always larger than the load.

Mechanical Advantage (MA)

The ratio of load to effort in a machine ($MA = \frac{\text{Load}}{\text{Effort}}$), measuring how much the machine assists the user.

Velocity Ratio (VR)

The ratio of the distance moved by the effort to the distance moved by the load in a mechanical system ($VR = \frac{\text{Distance effort moves}}{\text{Distance load moves}}$).

Integrated Circuit (IC)

A microscopic array of electronic circuits and components diffused or implanted onto the surface of a single crystal silicon chip.