Question

A car travels from town A to town B with a speed of 60 km/h and then returns back to A with a speed of 90km/h find
1) average speed for the whole journey
2) average velocity for the whole journey

Answer 1

@ Hey friend.....
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Have a look for your answer in the above pic:----

Hope it will help you!!
Thanks!!!
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Answer 2

Hope u like my process
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Speed = distance/time

Time = distance/speed.
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Let the total distance travelled be x.

So..
Time taken for travelling A to B=x/60 hr.

Time taken for travelling B to A = x/90 hr.

Average speed =
(total distance travelled) ÷ (total time taken)

$= \frac{x + x}{ \frac{x}{60} + \frac{x}{90} } \\ \\ = \frac{2x}{ \frac{3x + 2x}{180} } = \frac{2x}{5x} \times 180 \\ \\ = 2 \times 36 = 72 \: \: \: km \: \: {hr}^{ - 1}$
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Total displacement = (x) +(-x) =0 km

Average velocity
= (total displacement)÷( time taken)

$= \frac{0}{ \frac{x}{60} + \frac{x}{90} } \\ \\ = 0 \: \: km \: \: {hr}^{ - 1}$
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Hope this is ur required answer

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