A bullet train in Japan starting from rest accelerates uniformly in 0.5 m per second for 2 minutes then maintains uniform speed for 20 minutes and then Rita Di uniformly @ 0.25 M per second and comes to rest calculate the average speed of the train
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put formula and then valuw then ot will come
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V=u + a t
so V1= 0.5×2×60=60 m/s
s0=ut + 1/2 at^2= 1/2×0.5×2×60×2×60=3600 m
s1 =V1 ×t =60×(20×60)=72000m
then v2^2-v1^2=2as2
so s2=-60^2/2×-0.25=7200 m
also time of retardation= 60/0.25=15 sec
so total distance =3600+7200+72000=82800 m
so avg. speed =total distance/total time=82800/(120+1200+15)=67.48 m/s
so V1= 0.5×2×60=60 m/s
s0=ut + 1/2 at^2= 1/2×0.5×2×60×2×60=3600 m
s1 =V1 ×t =60×(20×60)=72000m
then v2^2-v1^2=2as2
so s2=-60^2/2×-0.25=7200 m
also time of retardation= 60/0.25=15 sec
so total distance =3600+7200+72000=82800 m
so avg. speed =total distance/total time=82800/(120+1200+15)=67.48 m/s
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