Physical Quantities

Derived Quantity

A physical quantity obtained from base quantities through mathematical relationships; for example, speed is derived from length and time.

Base Quantity

A fundamental physical quantity that cannot be defined in terms of other quantities; examples include length, mass, and time.

Prefix

A symbol that is used to indicate decimal sub-multiples and multiples of the SI units; examples include kilo (k), mega (M), and milli (m).

Standard Form

A way of expressing numbers where a number between 1 and 10 is multiplied by a power of 10.

Simple Pendulum

A device that swings back and forth used to measure time, with its period determined by the length of the pendulum and gravitational field strength.

Scalar Quantity

A physical quantity that has only magnitude, such as mass,energy, speed,distance and time

Vector Quantity

A physical quantity that has both magnitude and direction, such as velocity, displacement, acceleration, force and weight

Distance vs Displacement

Distance is a scalar quantity representing how much ground an object has covered, while displacement is a vector quantity representing the object's overall change in position.

Speed vs Velocity

Speed: It's the rate of change of distance over time that does not include direction, while Velocity: It's the rate of change of displacement over time, including direction.

Parallax Error

An error in measurement caused by the observer's angle of view, leading to inaccuracies in reading scales or dials.

measuring tape

accurate to 0.1cm or 1mm and measures up to several metres

metre rule

accurate to 0.1cm or 1mm and measures up to 1metre

digital calipers

accurate to 0.001cm or 0.01mm and measures up to 15centimetres

digital micrometer screw gauge

accurate to 0.0001cm or 0.001mm and measures up to 2.5cm