Boats and Streams overview

Easy Tips:
 
we know that Speed = distance/ time
=> from this we get distance = Speed*time
  & Time=distance/speed

Time---> hours,minutes,sec
Distance--->kilometers,meters
Speed----> kmph,mps.


=> One more  thing to remember all the parameters must be in 1 form.i.e., either in Kilometers for distance,hours for time or meters(distance) and time in sec
=>Check that  given values are of uniform values or convert them
             1Km=1000m
              1hr=60 min
by this in order to convert            Speed (km/hr)====> to Speed(m/sec)

      =>    we need to multiply the given value with 5/18
Eg: speed =18 km/hr= 18*(5/18) =5 m/sec


In the similar way,
          to convert speed in m/sec to  km/hr :
=> multiply the given value with 18/5

eg: 15m/sec speed = 54 km/hr

 Now,coming to the cases with Boats and Streams:

Let Speed of the man in Still water or Speed of boat in  Still water ="a"

Speed of current or Rate of Current = "b"


Downstream Speed = a+b
(since Downstream increases the speed and decreases the effort to ride the boat)

Upstream Speed =a-b
(Since its Difficult to ride in Upstream the person  has to use more effort)


Let the distance between source and distance be   "k"
now,
                      Time(Downstream) = k/(a+b)
                      Time(Upstream)=k/(a-b)


If the person travels from source to destination and again reaches to source then,


                       Time(Upstream+Downstream) =[k/(a+b)]+[k/(a-b)]
                                                                                                                      ........more updates will be updated soon...Gwtmi.. :)