Variable Extraction Guide
Common Keywords to Look For
Mechanics
| Keyword/Phrase |
Variable |
Symbol |
| "mass of", "weighs" |
Mass |
m |
| "speed", "velocity" |
Velocity |
v |
| "accelerates at", "acceleration" |
Acceleration |
a |
| "force of", "push/pull" |
Force |
F |
| "travels", "distance", "displacement" |
Displacement |
S |
| "in ... seconds", "time taken" |
Time |
t |
Electronics
| Keyword/Phrase |
Variable |
Symbol |
| "voltage", "potential difference" |
Voltage |
U |
| "current flow", "amperes" |
Current |
I |
| "resistance", "ohms" |
Resistance |
R |
| "capacitor", "capacitance" |
Capacitance |
C |
| "time constant", "RC time" |
Time |
t |
Watch Out For
- Unit Conversions
- milliseconds (ms) to seconds (s)
- microfarads (μF) to farads (F)
- BUT: kilograms (kg) is already SI, no conversion needed
- Implicit Information
- "At rest" means v = 0
- "Dropped" implies initial velocity = 0
- "Constant speed" means a = 0
- "Stops" or "comes to rest" means final velocity = 0
- Multiple Steps
- Some problems give you intermediate information
- Example: "accelerates for 5 seconds then maintains constant speed"
- Break these into separate calculations