Physics Unit Conversions
Convert between SI and Imperial units for length, mass, time, force, energy, and more. This guide covers key physics units, conversion tables, formulas, and practical examples.
Introduction
Physics uses a wide range of units to measure quantities like length, mass, time, force, energy, and power. Accurate conversions are essential for solving problems and understanding scientific data.
Key Physics Units
- Length: meter (m), kilometer (km), centimeter (cm), inch (in), foot (ft), mile (mi)
- Mass: kilogram (kg), gram (g), pound (lb), ounce (oz)
- Time: second (s), minute (min), hour (h)
- Force: newton (N), pound-force (lbf)
- Energy: joule (J), calorie (cal), kilowatt-hour (kWh), British thermal unit (BTU)
- Power: watt (W), horsepower (hp)
SI vs Imperial Units
- SI (International System) is the standard in science: meter, kilogram, second, etc.
- Imperial/US units are used in some countries: inch, foot, pound, etc.
Conversion Tables
Length
| Unit | To Meter (m) |
|---|
| 1 inch (in) | 0.0254 m |
| 1 foot (ft) | 0.3048 m |
| 1 mile (mi) | 1,609.34 m |
Mass
| Unit | To Kilogram (kg) |
|---|
| 1 ounce (oz) | 0.02835 kg |
| 1 pound (lb) | 0.4536 kg |
Force
| Unit | To Newton (N) |
|---|
| 1 lbf | 4.44822 N |
Energy
| Unit | To Joule (J) |
|---|
| 1 cal | 4.184 J |
| 1 kWh | 3,600,000 J |
| 1 BTU | 1,055.06 J |
Power
| Unit | To Watt (W) |
|---|
| 1 hp | 745.7 W |
Formulas
- Speed: v = d / t (distance / time)
- Force: F = m × a (mass × acceleration)
- Energy: E = F × d (force × distance)
- Power: P = W / t (work / time)
Example Conversions
- Convert 10 ft to m: 10 × 0.3048 = 3.048 m
- Convert 5 lb to kg: 5 × 0.4536 = 2.268 kg
- Convert 2 hp to W: 2 × 745.7 = 1,491.4 W
Tips
- Always check which unit system your problem uses.
- Use conversion factors for quick calculations.
- Online converters are helpful for complex conversions.
FAQ
- What is the difference between mass and weight? Mass is the amount of matter; weight is the force due to gravity (W = m × g).
- How do I convert between SI and Imperial units? Use the tables above or an online converter for accuracy.
