Breakthrough Physics: Measurements and Mechanics

A set of vocabulary flashcards based on the Table of Contents and introductory themes of the Breakthrough Physics A' Level text, covering units, dimensions, vectors, and Newtonian mechanics.

Physical Quantities

Properties of a phenomenon, body, or substance that can be quantified by measurement and expressed as a value with a unit.

Dimensions of a Physical Quantity

An expression that relates a physical quantity to the base quantities, commonly represented using symbols such as $[M]$ for mass, $[L]$ for length, and $[T]$ for time.

Principle of Homogeneity

A rule stating that the dimensions of all terms in a physical equation must be the same on both sides.

Accuracy

How close a measured value is to the true or accepted value of the quantity being measured.

Precision

A measure of the consistency or reproducibility of repeated measurements under the same conditions.

Significant Figures or Digits

The digits in a number that are known with confidence plus the first digit that is uncertain.

Adding and Subtracting Vectors

The process of finding the resultant vector by combining two or more vectors according to specific rules like the triangle or parallelogram law.

Resolution of Vectors into Components

The process of splitting a single vector into two or more independent parts, typically along the horizontal ($x$) and vertical ($y$) axes.

Vector Multiplication

Mathematical operations involving vectors, such as the scalar (dot) product or the vector (cross) product.

Fundamental Forces in Nature

The primary interactions that govern all physical processes, including gravity, electromagnetism, and the strong and weak nuclear forces.

A Free Body Diagram

A graphical representation used to show the relative magnitude and direction of all external forces acting on a specific object.

Turning Effect of a Force

A measure of the tendency of a force to rotate an object about an axis or pivot, commonly known as torque.

Centre of Gravity

The point at which the entire weight of a body may be considered to act.

Centre of Mass

The point in an object where its mass is concentrated and where all applied forces appear to act.

Rectilinear Motion

The motion of an object along a straight-line path.

Equations of Uniformly Accelerated Motion

The set of kinematic equations used to describe motion when acceleration remains constant, such as $v = u + at$.

Stopping Distances

The total distance a vehicle travels before it comes to a complete stop, calculated as the sum of thinking distance and braking distance.

Motion Under Gravity-Free Fall

The motion of an object where gravity is the only force acting upon it, resulting in an acceleration of approximately $9.81\,m/s^2$.

Motion in Two Dimensions-Projectile Motion

A form of motion where an object moves along a curved path under the constant influence of gravity.

Relative Motion

The motion of an object as observed from a specific reference frame or in relation to another moving object.

Newton's First Law of Motion

A law stating that an object will remain at rest or continue at a constant velocity unless acted upon by a non-zero resultant force.