Physics Lecture Notes: Unit Conversion and Prefixes

Introduction

• Focus on converting units of measurement using standard prefixes in physics.
• Example given for converting kilometers to millimeters.

Unit Conversion

• Base unit of length: meter (m).
• Prefixes modify the base unit by powers of 10.

Common Prefixes

• Giga (G): $10^9$
• Mega (M): $10^6$
• Kilo (k): $10^3$
• Centi (c): $10^{-2}$
• Milli (m): $10^{-3}$
• Micro (μ): $10^{-6}$
• Nano (n): $10^{-9}$

Example: Microamps to Amps

• Convert 27 microamps to amps.
• Microamps: $27 \times 10^{-6}$
• In standard form: $2.7 \times 10^{-5}$ amps

Example: Kilometers to Millimeters

1. Convert kilometers to meters:
   • 89.2 km
   • Multiply by kilo factor: $89.2 \times 10^3$ meters
2. Convert meters to millimeters:
   • Millimeter prefix is $10^{-3}$
   • Convert by dividing by the milli factor:
   • $89.2 \times 10^3$ meters to millimeters
   • Result: $89.2 \times 10^6$ millimeters

Conclusion

• Understanding and using prefixes correctly is essential for proper unit conversion in physics.
• Practice converting between different units to gain confidence.