Year 10 Forensics: Physics and Chemistry Revision

Comprehensive vocabulary flashcards covering the physics and chemistry modules for Year 10 Forensics, including Redox, Motion, Falling bodies, and Enthalpy.

Scalar Quantity

A physical measurement described solely by magnitude without an associated direction, such as speed or distance.

Vector Quantity

A physical measurement characterized by having both magnitude and direction, such as force and velocity.

Newton's Second Law of Motion

The principle stating that the resultant force acting on an object equals the mass of the object multiplied by its acceleration ($F = ma$).

Gravitational Potential Energy (GPE)

The energy stored in an object due to its vertical position or height within a gravitational field, calculated by multiplying weight by height ($E_p = mgh$).

Work Done

The energy transferred when a force moves an object across a distance, represented by the relationship $\text{Work done} = \text{force} \times \text{distance}$.

Braking Distance

The distance traveled by a vehicle from the moment the brakes are applied until the vehicle comes to a complete standstill.

Terminal Velocity

The constant maximum speed achieved by a falling body when the upward drag force of air resistance equals the downward pull of gravity (weight), resulting in zero acceleration.

Galvanic Cell

An electrochemical cell that produces an electrical potential from spontaneous redox reactions, composed of two half-cells, an external circuit, and an internal circuit.

Anode

The electrode in an electrochemical cell at which oxidation takes place and from which electrons flow into the external circuit.

Cathode

The electrode in an electrochemical cell at which reduction takes place and toward which cations migrate within the solution.

Salt Bridge

An internal circuit component—often a strip soaked in an inert electrolyte such as $\text{KCl}$—that balances ionic charge differences between half-cells without reacting with the electrodes or electrolytes.

Reactivity Series

An empirical ranking of metals by chemical reactivity; in simple cells, a larger difference in reactivity between the two metal electrodes produces a higher cell voltage.

Combustion

An exothermic reaction requiring fuel, heat, and oxygen ($\text{O}_2$) that releases energy in the form of heat and light.

Enthalpy

A thermodynamic property representing the total heat content of a chemical system at constant pressure.

Enthalpy of Combustion

The heat energy released per mole of a substance when it undergoes complete combustion in the presence of oxygen.

Angle of Impact (Blood Spatter)

The acute internal angle at which a blood droplet strikes a surface, determined using the trigonometric formula $\sin(\theta) = \frac{\text{width}}{\text{length}}$.

Area of Convergence

The two-dimensional intersecting point where straight lines drawn through the long axes of blood spatter droplets meet, revealing the location of the impact source.

Covalent Bond

A chemical link formed by the sharing of valence electron pairs between non-metal atoms, such as the bonds holding together methane ($\text{CH}_4$).