It took a stopping train 41/4min to travel between two stations 11.2km apart.The train accelerated uniformly during the first 11/4min of the journey,and decelerated uniformly to rest during the last 3/2min of the journey.The train had moved with uniform speed during the remaining part of its travel.calculate (a)Uniform speed,km/h (b)Uniform acceleration (c)Uniform retardation (d)Distance travelled in the first 4min of the journey (c)Distance covered in the last 3min of the journey.

1 answer

assume the maximum velocity was V.

Then the average velocity during starting and stopping was V/2.

So, during starting, you know the avg velocity, and time, so

distancestarting=v/2 * 11/4*1/60 in km if v is in km/hr

distancestopping= v/2*3/2*1/60

distance constant speed=11.2-v/120(11/4+6/4)

time constant speed= 41/4-11/4-3/2 min
convert that to hours.

velocity v= distanceconstantspeed/timeconstant speed
from that calculate v.

Everything else ought to work out easily.