Measurement of Time and Motion

Motion, Distance & Speed – Solved Numericals

Question 1

A car moves 150 m in 10 s. What is its speed in kilometres per hour (km/h)?

Click for solution

1. Formula → Speed = Distance ÷ Time
2. Put numbers → 150 m ÷ 10 s = 15 m/s
3. Convert → 1 m/s = 3.6 km/h
4. 15 m/s × 3.6 = 54 km/h

Speed = 54 km/h

Question 2

Runner A covers 400 m in 50 s. Runner B covers 400 m in 45 s.

(a) Find each runner’s speed.
(b) Who is faster and by how much?

Click for solution

Runner	Calculation	Speed (m/s)
A	400 m ÷ 50 s	8
B	400 m ÷ 45 s	8.89

Runner B is faster by 0.89 m/s (≈3.2 km/h).

Question 3

A train runs at 25 m/s. How long will it take to cover 360 km?

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1. Convert speed → 25 m/s × 3.6 = 90 km/h
2. Time = Distance ÷ Speed = 360 km ÷ 90 km/h
3. Time = 4 h

It takes 4 hours.

Question 4

A train travels 180 km in 3 h.

(i) Speed in km/h
(ii) Speed in m/s
(iii) Distance in 4 h at same speed

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1. (i) 180 km ÷ 3 h = 60 km/h
2. (ii) 60 km/h ÷ 3.6 = 16.67 m/s
3. (iii) 60 km/h × 4 h = 240 km

(i) 60 km/h   (ii) 16.67 m/s   (iii) 240 km

Question 5

The fastest horse runs 18 m/s. A train moves 72 km/h. Which is faster and by how much?

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1. Horse → 18 m/s × 3.6 = 64.8 km/h
2. Difference → 72 − 64.8 = 7.2 km/h

Train is faster by 7.2 km/h (≈2 m/s).

Question 6

Explain, with examples, the difference between uniform and non-uniform motion.

Click for explanation

• Car on an empty highway keeps one steady speed → uniform motion.
• Car in city traffic speeds up, slows, stops → non-uniform motion.

Question 7

Fill the missing distance. The motion is uniform.

Time (s)	0	10	20	30	40	50	60	70
Distance (m)	0	8	16	24	32	?	48	56

Click for solution

1. Speed = 8 m / 10 s = 0.8 m/s
2. Distance at 50 s = 0.8 m/s × 50 s = 40 m

Missing distance = 40 m.

Question 8

A cyclist rides 60 km, 40 km, and 80 km in three successive hours.

(a) Is the motion uniform?
(b) Find the average speed.

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1. Different distances each hour → non-uniform motion.
2. Total distance = 60 + 40 + 80 = 180 km.
3. Total time = 3 h ⇒ Avg speed = 180 km ÷ 3 h = 60 km/h.

(a) Non-uniform   (b) Average speed = 60 km/h

Question 9

Write three everyday examples of non-uniform motion.

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1. Walking to school (stop at crossings).
2. Bus in city traffic.
3. Cycling on a busy road.

Question 10

Table of a walker’s journey:

Time (s)	0	20	40	60	80	100
Distance (m)	0	10	23	39	95	131

(a) Is the speed uniform?
(b) Find average speed in m/s and km/h.

Click for solution

1. Unequal jumps → speed is non-uniform.
2. Average speed = Total distance ÷ Total time.
3. 131 m ÷ 100 s = 1.31 m/s.
4. 1.31 m/s × 3.6 ≈ 4.7 km/h.

(a) Non-uniform   (b) 1.31 m/s (≈ 4.7 km/h)

Question 11

A 2000 m race must finish in 200 s.

The runner covers:
• first 500 m at 10 m/s
• next 500 m at 5 m/s

(a) Time left for last 1000 m?
(b) Required speed for last 1000 m?
(c) Average speed for whole race?

Click for solution

1. First 500 m → 500 m ÷ 10 m/s = 50 s.
2. Next 500 m → 500 m ÷ 5 m/s = 100 s.
3. Time used = 150 s ⇒ Time left = 200 − 150 = 50 s.
4. Required speed = 1000 m ÷ 50 s = 20 m/s.
5. Average speed = 2000 m ÷ 200 s = 10 m/s (36 km/h).

(a) 50 s left   (b) Need 20 m/s   (c) Avg = 10 m/s

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