Question

A body travels 54km/hr for 1 hour and travels 2 hour with speed 72/hr and 90km/hr .Calculate the avg speed

Answer 1

C.Q-A body travels with the speed of 54km/hr for first 1 hour and travels the second 1 hour with speeds 72 km/ hr and 90km/ hr. calculate the average speed of whole journey.

For first 1 hour:
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let the speed of body x = 54 km/ hr

For second 1 hour:
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let average speed of body

y = (72 + 90)/ 2=162 ÷ 2 = 81 km/ hr

required average:
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required average speed

=( xt1 + yt2)/ (t1 + t2 )

here ,t1 = 1hr = t2

Average speed = (54 × 1 + 81 × 1)/ (1 + 1 )

= (54 + 81 )/ 2 = 135 ÷ 2

= 67.5 km/ hr

Answer:
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average speed of body= 67.5km/ hr
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