Question

Abdul, while driving to school, computes the speed for his trip to be 20 km/h. On his return trip along the same route, there is less traffic and the average speed is 30 km/h. What is the average speed for Abdul’s trip?

Answer 1

Answer:

ok

On his return trip along the same route, there is less traffic and the average speed is 30kmh−1. And we are asked to find the average velocity of Abdul on the trip. Thus, we can say that the average speed of Abdul in trip is 24 kmh−1.

Explanation:

Answer 2

Let us assume that Abdul is travelling 'x' kilometer distance while going to school.

Distance = Speed × Time

$1) when \: its \: average \: speed \: is \: \\ 20km |hr = \\ x = v1 \times t1 = 20 \times t1 \\ 2)when \: its \: average \: speed \: is \\ 30km|hr = \\ x = v2 \times t2 = 30 \times t2 \\ v \: average = \\ \frac{total\:distance\:travelled }{total \: time \: taken} \\ v \: average = \\ \frac{x + x}{ \frac{x}{v1} + \frac{x}{v2} } = \frac{2x}{ \frac{x}{20} + \frac{x}{30 } } = \\ \\ = 24 \: km \: {h}^{ - 1}$

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