Physics: Forces & Motion

Vocabulary-style flashcards covering core physics concepts including scalars, vectors, SI units, kinematics, and Newton's Three Laws of Motion.

Scalar Quantities

A physical quantity that has magnitude only, such as mass, distance, or time.

Vector Quantities

A physical quantity that has both magnitude and direction, such as force, velocity, or displacement.

Metre (m)

The SI unit for length or distance.

Newton (N)

The SI unit for force, where $1\,N = 1\,kg \times 1\,m/s^2$.

Pascal (Pa)

The SI unit for pressure.

Mega (M)

A metric prefix representing a value of $10^{6}$.

Micro ($\mu$)

A metric prefix representing a value of $10^{-6}$.

Nano (n)

A metric prefix representing a value of $10^{-9}$.

Screw Gauge

A measuring device used for very small objects.

Vernier Caliper

A measuring device used for small objects with precision.

Parallax Error

An error in measurement prevented by keeping the eyes at eye level when reading a scale.

Lower Meniscus

The bottom of the curve formed by a liquid in a measuring cylinder, which must be read to calculate volume accurately.

Newton Meter

A device used for measuring force or weight.

Light Gate

A device used to measure instantaneous speed.

Velocity

The rate of change of displacement, defined as speed plus direction ($v = \frac{s}{t}$).

Displacement (s)

A vector quantity representing the change in position from an origin.

Acceleration (a)

The change in velocity divided by time, expressed by the formula $a = \frac{v - u}{t}$.

Deceleration

The opposite of acceleration, represented as negative acceleration meaning an object is slowing down.

Slope of a Displacement-time (s-t) Graph

The value calculated as $m = \frac{\Delta s}{\Delta t}$, which represents the velocity ($v$).

Slope of a Velocity-time (v-t) Graph

The value calculated as $m = \frac{\Delta v}{\Delta t}$, which represents the acceleration ($a$).

Area under the v-t slope

Calculated as $\Delta v \times \Delta t$, this value represents the displacement ($\Delta s$) or total distance travelled.

Terminal Velocity

The constant velocity reached when weight equals air resistance ($W = A.R.$), resulting in a resultant force of zero and zero acceleration.

Gravitational Field Strength (g)

The downward acceleration of every falling object (ignoring air resistance), valued at $10\,m/s^2$.

Normal Force

A contact force exerted by a surface on an object, acting perpendicular to the surface.

Friction Force

A contact force that opposes motion between surfaces in contact.

Thrust

A pushing force produced by engines, propellers, or other propulsion methods.

Resultant Force

The net or final force acting on an object, calculated by finding the difference between unequal forces.

Newton's First Law of Motion

States that an object remains at rest or moves with constant velocity unless acted upon by a resultant force.

Newton's Second Law of Motion

States that when there is a resultant force, an object accelerates, described by the formula $F = ma$.

Newton's Third Law of Motion

States that every action force has an equal-magnitude and opposite-direction reaction force.

Weight (W)

The gravitational force calculated by mass times gravitational field strength ($W = mg$).