Natural Science and Technology: Mechanical Systems Lecture Review

Vocabulary-style flashcards covering the key concepts of technology, mechanical systems (levers, pulleys, wheel and axle), hydraulic and pneumatic systems, and CAPS assessment guidelines.

Technology (CAPS Definition)

The use of knowledge, skills, values and resources to meet people’s needs and wants by developing practical solutions to problems, taking social and environmental factors into consideration.

Mechanical System

A system made up of components that work together to transmit forces and movement in order to perform a task.

Force

A push or pull that causes an object to move, stop, change direction, or change shape.

Mechanical Advantage

A measure of how a machine makes work easier by reducing the amount of force needed or changing the direction of the force; calculated as $\text{Mechanical Advantage} = \frac{\text{Output force}}{\text{Input force}}$.

Rotational movement

Circular motion produced by mechanical systems, such as wheels, gears, and pulleys.

Linear movement

Straight-line motion produced by mechanical systems, such as pistons or sliding doors.

Oscillating movement

Back-and-forth motion produced by mechanical systems, such as a seesaw.

Wheel and Axle

A simple mechanical system consisting of two circular parts of different sizes (a wheel and a smaller rod or cylinder) that rotate together to make work easier.

Lever

A simple machine consisting of a rigid bar that rotates around a fixed point called a fulcrum to lift or move a load using an applied force.

Fulcrum

The fixed point or pivot around which a lever arm rotates.

Load (Resistance)

The weight or object to be moved in a lever or mechanical system.

Effort (Input Force)

The force applied to a mechanical system to move the load.

First-Class Lever

A lever where the fulcrum is located between the input effort and the output load; examples include seesaws and scissors.

Second-Class Lever

A lever where the load is located between the fulcrum and the effort; examples include wheelbarrows and nutcrackers.

Third-Class Lever

A lever where the effort is applied between the fulcrum and the load; examples include tweezers and fishing rods.

Law of the Lever

The principle that balance occurs when moments are equal and opposite, expressed as the formula $F1 \times D1 = F2 \times D2$.

Pulley

A simple machine consisting of a wheel with a groove around which a rope or cable passes, designed to change the direction of force.

Fixed Pulley

A pulley attached to a fixed support that changes the direction of the force but does not reduce the effort required.

Movable Pulley

A pulley that moves with the load, reducing the effort needed to lift it with a mechanical advantage typically equal to $2$.

Block and Tackle

A compound pulley system made up of fixed and movable pulleys that greatly reduces the effort needed for lifting heavy loads.

Work

The product of force and distance, calculated using the formula $W = F \times D$ and measured in Joules $(J)$.

Hydraulic System

A system that uses incompressible liquid, such as oil or water, under pressure to perform work and transmit force.

Pneumatic System

A system that uses compressed air or gas to perform work; these systems are often faster than hydraulic systems but less powerful.

Pascal’s Law

The mechanical principle stating that pressure applied to a fluid at one point is transmitted to another point in the system.

Jaws of Life

A hydraulic rescue tool used to cut, spread, or lift vehicles in accidents to free trapped individuals.

Technology Process Skills

The five core skills used in the CAPS Technology curriculum: Investigate, Design, Make, Evaluate, and Communicate.

Mini-PAT

A mini Practical Assessment Task used for formal sumative assessment in Grade 7 Technology.