Question 1 - Speed of a Car in km/h - Questions at the end of the chapter - Chapter 8 Class 7 - Measurement of Time and Motion (Curiosity)

Question. Calculate the speed of a car that travels 150 metres in 10 seconds. Express your answer in km/h.

Answer.

Use the formula: Speed = Distance ÷ Time

$$\begin{aligned} \text{Speed} &= \frac{\text{Distance}}{\text{Time}} \\[8pt] &= \frac{150 \text{ m}}{10 \text{ s}} \\[8pt] &= 15 \text{ m/s} \end{aligned}$$

To convert m/s to km/h, multiply by 18/5:

$$\begin{aligned} \text{Speed in km/h} &= 15 \text{ m/s} \times \frac{18}{5} \\[8pt] &= 54 \text{ km/h} \end{aligned}$$

The speed of the car is 15 m/s or 54 km/h .