A car moves a distance of 200m. It covers first half ofthe distance at speed 60 kmh-1 and the second half atspeed v. If the average speed is 40 kmh-1, the value of v is
Answer :- E
Solution :- First half of distance = 100m
speed = 60km/h or 150/9 m/s
so time taken= 100÷ 150/9
= 6 second
Given avg speed = 40km/h
= 100/9 m/s
Distance= 200m, so total time is 18s
now 9 s has passes covering 100 m. time left = 12s
Distance left = 100m
so speed(v) = 100/12
= 50/6 m/s or 30 km/h
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