Question

A particle moves along X-axis with speed
6 m/s for the first half distance of a journey and the
second half distance with a speed 3 m/s. The
average speed in the total journey is​

Answer 1

Answer:

4 m/s

Explanation:

Let total distance of journey by S

Time taken for first half journey

t1 = Distance / Speed

= (S/2) / 6

= S/12

Time taken for second half journey

t2 = Distance / Speed

= (S/2) / 3

= S/6

Average speed = Total distance / Total time

= S / (t1 + t2)

= S / (S/12 + S/6)

= S / [S(1/12 + 1/6)]

= 1 / (1/12 + 1/6)

= 1 / (1/12 + 2/12)

= 1 / (3/12)

= 12 / 3

= 4 m/s