A Level Physics CIE - Physical Quantities & Units

These flashcards cover key concepts related to physical quantities and units in A Level Physics.

Physical Quantity

A quantity that has both a numerical magnitude and a unit.

SI Unit

The International System of Units used for measuring physical quantities.

Derived Units

Units that are derived from the seven SI Base units.

Scalar Quantity

A quantity with only magnitude, such as distance.

Vector Quantity

A quantity with both magnitude and direction, such as displacement.

Precision

The closeness of measured values to each other.

Accuracy

The closeness of a measured value to the true value.

Random Error

Unpredictable fluctuations in measurements caused by uncontrollable factors.

Systematic Error

Errors that arise from faulty instruments or flawed experimental methods.

Zero Error

A systematic error that occurs when an instrument reads a value when the true measurement is zero.

Absolute Uncertainty

Uncertainty expressed as a fixed quantity.

Fractional Uncertainty

Uncertainty expressed as a fraction of the measurement.

Percentage Uncertainty

Uncertainty expressed as a percentage of the measurement.

Metre Rule

An instrument used to measure distance and length.

Vernier Calipers

A tool used to measure the length, diameter, and thickness of objects.

Micrometer Screw Gauge

An instrument to measure small widths, thicknesses, or diameters with high precision.

Homogeneity of Equations

The property that requires both sides of a physical equation to have the same units.

Combining Vectors

The process of adding or subtracting vectors, represented graphically by arrows.

Components of a Vector

The horizontal and vertical parts of a vector when resolved into simpler vectors.

Physical Quantity

A quantity that has both a numerical magnitude and a unit.

SI Unit

The International System of Units used for measuring physical quantities.

Derived Units

Units that are derived from the seven SI Base units.

Scalar Quantity

A quantity with only magnitude, such as distance.

Vector Quantity

A quantity with both magnitude and direction, such as displacement.

Precision

The closeness of measured values to each other.

Accuracy

The closeness of a measured value to the true value.

Random Error

Unpredictable fluctuations in measurements caused by uncontrollable factors.

Systematic Error

Errors that arise from faulty instruments or flawed experimental methods.

Zero Error

A systematic error that occurs when an instrument reads a value when the true measurement is zero.

Absolute Uncertainty

Uncertainty expressed as a fixed quantity.

Fractional Uncertainty

Uncertainty expressed as a fraction of the measurement.

Percentage Uncertainty

Uncertainty expressed as a percentage of the measurement.

Metre Rule

An instrument used to measure distance and length.

Vernier Calipers

A tool used to measure the length, diameter, and thickness of objects.

Micrometer Screw Gauge

An instrument to measure small widths, thicknesses, or diameters with high precision.

Homogeneity of Equations

The property that requires both sides of a physical equation to have the same units.

Combining Vectors

The process of adding or subtracting vectors, represented graphically by arrows.

Components of a Vector

The horizontal and vertical parts of a vector when resolved into simpler vectors.

Resolving Vectors

Breaking down a vector into its horizontal and vertical components. This is often done using trigonometric