Скачать или смотреть IGCSE Physics Chapter 1: Making Measurements Sumarized

1. Measuring Length and Volume
🔸 Measuring Length:
Basic tool: Ruler (accuracy: ±1 mm)

More precise tools:

Vernier calipers (accuracy: ±0.1 mm)

Micrometer screw gauge (accuracy: ±0.01 mm)

Always take readings perpendicular to the scale to avoid parallax error.

🔸 Measuring Volume:
Regular objects: Use formulae like:

Cube:
𝑉
=
𝑙
×
𝑏
×
ℎ
V=l×b×h

Cylinder:
𝑉
=
𝜋
𝑟
2
ℎ
V=πr
2
h

Irregular objects: Use displacement method:

Submerge object in water in a measuring cylinder.

Volume displaced = volume of object

When measuring liquids, read the bottom of the meniscus at eye level.

⚖️ 2. Density
Definition:

Density
=
Mass
Volume
Density=
Volume
Mass
​

Units:

kg/m³ (SI unit)

g/cm³ (common lab unit; 1 g/cm³ = 1000 kg/m³)

Mass: Measured using a digital balance.

Volume:

Regular solids: use geometry

Irregular solids: use water displacement

Important concepts:

Substances with higher density than water sink.

Same mass but smaller volume = higher density

⏱️ 3. Measuring Time
Use a digital stopwatch or light gates for more precise timing.

Common sources of error:

Reaction time when using manual stopwatch

Irregular intervals or delay in starting/stopping

Improve accuracy by:

Repeating and taking averages

Using automatic timers or data loggers

🧠 Key Terms to Remember
Length, volume, mass, density, displacement, vernier caliper, micrometer, meniscus, stopwatch, light gate, accuracy, precision, parallax error

This is an AI-assisted educational video.