Question

1. amir travels half of his journey by bus at a speed of 200/9m/s and half of his journey by metro at 120km/h. calculate his average speed over the entire journey.

Answer 1

so the required solution is 80/3 m/s

Answer 2

Answer: Amir's average speed over the entire journey is 80/3 m/s.

Explanation:

Given that:

He covers half of the journey at speed:

$s_{1}=\frac{200}{9}$

Rest half of the journey at speed:

$s_{2}=120km/h=\frac{300}{9}$

We have to find the average speed.

Finding the average speed:

Let the total distance travel by Amir be 2x.

Time taken to travel to cover the first half be $t_{1}$ .

We know that;

• time=distance/speed

Therefore, $t_{1}=\frac{x}{\frac{200}{9} }$

Similarly, time taken to travel the second half be $t_{2}$ .

So, $t_{2}=\frac{x}{\frac{300}{9} }$

Now, adding both the equation we get;

$t_{1} +t_{2} =\frac{9x}{200} +\frac{3x}{100} =\frac{15x}{200}$

Average speed,  $s=\frac{2x}{\frac{15x}{200} }$

By solving, we get;  $s=\frac{80}{3}$

Hence, the average speed is 80/3 m/s.