# physics

posted by .

a train starts from rest and accelerates uniformly to achieve a velocity of 20m/sec in 10 sec.then train maintains this speed for next 200 sec.the breaks are then applied and train comes to rest in next 50 sec.calculate
a)acceleration in first 10 sec.
b)acceleration in last 50 sec.
c)the total distance traveled by the train in whole journey
d)average velocity of the trip.

• physics -

a. (V-Vo)/t = (20-0)/10 = 2 m/s^2.

b. a=(V-Vo)/t = (0-20)/50 = -0.4 m/s^2.

c. d1 = 0.5a*t^2 = 1*10^2 = 100 m.
d2 = 20m/s * 200s = 4000 m.

d3 = Vo*t + 0.5a*t^2
d3 = 20*50 + (-0.2)*50^2 = 500 m.

d1+d2+d3 = 100 + 4000 + 500 = 4600 m. = Total dist. traveled.

d. T = t1 + t2 + t3 = 10 + 200 + 50 = 260 s.

Va = (d1+d2+d3)/T = 4600m / 260 = 17.7
m/s. = Average velocity.

## Similar Questions

1. ### physics

a car traveled at uniform velocity of 20m/sec for 5 sec the brakes are applied and car retards uniformly and come to rest in further 8 sec.find a)distance traveled in first five sec b)distance traveled after breaks are applied c)total …
2. ### physics

a body moves with a uniform velocity of 2m/sec for 5 sec then velocity was uniformly accelerated and a velocity of 10m/sec was achieved in next 5 sec.then brakes were applied uniformly and body comes to rest in next 10 sec.calculate …
3. ### physics

a cyclist start from rest and accelerate uniformly to achieve a velocity of 12m/sec in 5 sec.immediately he applied brake and come to rest in next 4 sec .calculate a)distance traveled during acceleration b)distance traveled during …
4. ### physics

a train starts from rest and accelerates uniformly at 100m/min^2 for 10 min.then it maintains a constant velocity for remaining 20 min.brakes are applied and train uniformly retards and comes to rest in next 5 min. a)the maximum velocity …
5. ### physics

a train starts from rest and accelerates uniformly at 100m/min^2 for 10 min.then it maintains a constant velocity for remaining 20 min.brakes are applied and train uniformly retards and comes to rest in next 5 min. a)the maximum velocity …
6. ### physics

a train starts from rest and accelerates uniformly to achieve a velocity of 20m/sec in 10 sec.then train maintains this speed for next 200 sec.the breaks are then applied and train comes to rest in next 50 sec.calculate a)acceleration …
7. ### physics

a train starts from rest and accelerates uniformly at 100m/min^2 for 10 min.then it maintains a constant velocity for remaining 20 min.brakes are applied and train uniformly retards and comes to rest in next 5 min. a)the maximum velocity …
8. ### physics

a train starts from rest and accelerates uniformly to achieve a velocity of 20m/sec in 10 sec.then train maintains this speed for next 200 sec.the breaks are then applied and train comes to rest in next 50 sec.calculate a)acceleration …
9. ### physics

a car starts from rest and attains a velocity of meter/sec,then acceleration changes and it aquires the velocity of 20meter/sec in next 5sec .then it slows down and comes to rest in next 5sec.draw a velocity-time graph for the given …
10. ### Physics

the engineer of a passenger train traveling at 100 ft/sec sights a freight train whose caboose is 600 ft ahead of the same track. The freight train is traveling in the same direction as the passenger train with a velocity of 30 ft/sec. …

More Similar Questions