Time, Speed and Distance
- Formula / Rule
- Time, Speed and Distance
- Topic
- Time, Work & Speed
- Formula
Speed = $\frac{\text{Distance}}{\text{Time}}$ Distance = $\text{Speed} \times \text{Time}$ Time = $\frac{\text{Distance}}{\text{Speed}}$
Average Speed = $\frac{\text{Total Distance}}{\text{Total Time}}$
Conversion:
- $\text{km/h} \to \text{m/s}$: multiply by $\frac{5}{18}$
- $\text{m/s} \to \text{km/h}$: multiply by $\frac{18}{5}$
Relative speed:
- Same direction: $|S_1 - S_2|$
- Opposite direction: $S_1 + S_2$
- When to Use
- Solving train, boat, or car problems involving time, speed, and distance.
- Worked Example
Q: A train travels $180 \text{ km}$ in $3 \text{ hours}$. Find its speed.
$\text{Speed} = \frac{180 \text{ km}}{3 \text{ hours}} = 60 \text{ km/h}$ $\text{In m/s} = 60 \times \frac{5}{18} \approx 16.67 \text{ m/s}$