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Question
A train travels 180 km in 3 h. Find its speed in: (i) km/h (ii) m/s (iii) What distance will it travel in 4 h if it maintains the same speed throughout the journey?
🔗 Concepts: 8.3 Speed | 8.3.1 Speed–Distance–Time
Train: 180 km in 3 h — find speed in km/h, m/s, and distance in 4 h.
![Question 4 - A train travels 180 - Measurement of Time an - [Teachoo] - Questions at the end of the chapter](https://cdn.teachoo.com/test/1ff7f765-2e92-4028-a116-0e9276ec16e1/image-a-unit-conversion-chart-km-h-to-m-s-next-to-a-train-travelling-180-km-in-3-h.png)
Show Answer
(i) 60 km/h (ii) ≈ 16.67 m/s (iii) 240 km
Explanation
📋 Given
- Distance = 180 km
- Time = 3 h
🔄 Unit Conversion (for part ii)
- km/h → m/s: multiply by 1000, divide by 3600.
- Shortcut: divide km/h by 3.6 to get m/s.
📐 Formulas Used
(i, ii) Speed = Distance ÷ Time
(iii) Distance = Speed × Time
Step 1 — Speed in km/h
$$\text{Speed} = \frac{180 \text{ km}}{3 \text{ h}} = \boxed{60 \text{ km/h}}$$
Step 2 — Convert km/h to m/s
Multiply by 1000 (km → m) and divide by 3600 (h → s).
$$60 \text{ km/h} = \frac{60 \times 1000}{3600} = \boxed{\frac{50}{3} \approx 16.67 \text{ m/s}}$$
Step 3 — Distance in 4 h
$$\text{Distance} = 60 \text{ km/h} \times 4 \text{ h} = \boxed{240 \text{ km}}$$
Speed = 60 km/h = 16.67 m/s — distance in 4 h = 240 km.
