a train starts from rest and accelerates uniformly at 100 min-2 for 10 min .It then maintains a constant velocity for 20 minutes.the brakes are then applied,and the train is uniformly retarded.it comes to rest in 5 min. draw a velocity time graph find the maximum velocity reached, the retardation in the last 5min. , the total distance traveled and the average velocity ms-² taking=10ms-²

a train starts from rest and accelerates uniformly at 100 min-2 for 10

1.	a train starts from rest and accelerates uniformly at 100 min-2 for 10 min .It then maintains a constant velocity for 20 minutes.the brakes are then applied,and the train is uniformly retarded.it comes to rest in 5 min. draw a velocity time graph find the maximum velocity reached, the retardation in the last 5min. , the total distance traveled and the average velocity ms-² taking=10ms-²
Answer» CORRECT option isC17.69ms −1 TOTAL distance covered(s) = Distance during acceleration(s 1 ) + distance during uniform motion(s 2 ) + distance during retardation(s 3 )For acceleration,v=u+a∗tv MAX =2×10=20 m/ss=ut+(1/2)at 2 s 1 =(1/2)×2×10 2 =100 mFor uniform motion,s=vts 2 =20×200 =4000 mDuring retardation,v=u+at0=20+50t =−0.4 m/s 2 s 3 =ut+(1/2)at 2 =20×50+(1/2)×(−0.4)×50 2 =500 mTotal distance travelled, s=s1+s2+s3=100+4000+500=4600 mTotal time taken, t=t 1 +t 2 +t 3 =260 sAverage velocity, v avg = Total TIMETOTAL DDistan =4600/260=17.69 m/s