Jaza

Definition: Density = mass per unit volume.

Symbol: ρ\rhoρ (rho).

Formula: ρ=mV\rho = \frac{m}{V}ρ=Vm​.

SI Unit: kg/m³ (also g/cm³).

Concept: Denser objects have more mass packed into the same space.

Measuring density:

Measure mass with a balance.

Measure volume (by formula for regular objects, displacement for irregular ones).

Measuring volume: easuring Volume

• Regular objects (e.g. cube, cylinder).→ LxBxH.

• Irregular objects → displacement method:

  Displacement method to find volume:

  1. Fill a measuring cylinder with water.

  2. Note the initial water level.

  3. Gently lower the object fully into the water.

  4. Note the new water level.

  5. Volume of object = final water level – initial water level.

  6. Unit: cm³ or mL. Measuring Time

     • Analogue clock: uses hands on a dial

     • Digital clock: shows numbers directly

     Measuring Short Time Intervals

     • Use a simple pendulum

     • Count a large number of oscillations (e.g. 20 or 30)

     • Measure total time with a stopwatch

     • Calculate time period:

       Time period of one oscillation = total time ÷ number of oscillations