Physical Quantities and Laws of Motion

Fundamental Quantities

Length (m)

Time (s)

Mass (Kg)

Derived Quantities

Surface Area (m²)

Volume (m³)

Scalar Quantities

Magnitude

Ex: Speed, distance, time, mass

Vector Quantities

Magnitude and direction

Ex: Displacement, velocity, acceleration

First Law of Motion

Inertia

Objects at rest stay at rest; objects in motion stay in motion (unless acted upon by external force)

Second Law of Motion

Explains how forces cause objects to change their state of motion

More force means more acceleration, but heavier objects need more force to accelerate

F = Mass x Acceleration

Third Law of Motion

Action-Reaction

Every action has an equal and opposite reaction

Mass

Amount of matter in an object (constant)

Weight

Force due to gravity acting on mass

Potential Energy

Stored energy (Gravitational or spring)

Kinetic Energy

Energy of motion

Conservation of Energy

Total energy remains constant unless external work is applied

Work

Force x Distance

Measured in Joules

Power

Rate of energy transfer

Measured in watts

Amplitude

Intensity of sound (dB)

Sound Intensity

Power per unit area (W/m²)

Physical Measures

Frequency, amplitude, phase

Perceptual Measures

Pitch, loudness, timbre