Units Measurements
⚡ Units & Measurements – 60-Second Cheat Sheet
🔑 Funda-Funda
SI Base Units (7 only)
- Length: metre (m)
- Mass: kilogram (kg)
- Time: second (s)
- Electric current: ampere (A)
- Temperature: kelvin (K)
- Luminous intensity: candela (cd)
- Amount of substance: mole (mol)
Derived Hot-Shots
- Force: newton (N) = kg·m·s⁻²
- Energy: joule (J) = N·m
- Power: watt (W) = J·s⁻¹
- Pressure: pascal (Pa) = N·m⁻²
- Frequency: hertz (Hz) = s⁻¹
- Charge: coulomb (C) = A·s
📏 1-Liner Conversion Table (Railway Fav.)
| Unit | ⇄ | SI Unit | Memory Trigger |
|---|---|---|---|
| 1 Å | 10⁻¹⁰ m | “Angry Ant = 10 negative ten” | |
| 1 micron | 10⁻⁶ m | “Micro-soap kills 6 germs” | |
| 1 light-year | 9.46×10¹⁵ m | “Light-16 sweet” | |
| 1 astronomical unit (AU) | 1.496×10¹¹ m | “Earth–Sun 150 million km” | |
| 1 parsec | 3.26 light-year | “Par-sec = tri-sec (3)” | |
| 1 tonne | 1000 kg | “T for Thousand” | |
| 1 carat | 200 mg | “Car-200” | |
| 1 acre | 4047 m² | “4–0–4–7” | |
| 1 horsepower | 746 W | “Horses 747 fly” |
🧠 Mnemonics
- King Henry Died Drinking Chocolate Milk
k- h- da- base- d- c- m- (km➜mm) - My Damn Cat Shits Every Morning
m- dm- cm- mm- µm- nm (descending)
📐 Dimensionless & Special
- Relative density, strain, angle, refractive index → no unit
- 1 nautical mile = 1.852 km (railway track charts)
- 1 knot = 1 nautical mile/h = 0.514 m/s
⚠️ Common Traps
- Weight ≠ Mass; weight = mg → unit newton
- Calorie (small) = 4.18 J; kcal = 4180 J
- 1 barrel (oil) = 159 L
BETA
