TIME AND DISTANCE FORMULAS- :
1.The Relation between Time,Distance and Speed is , Distance=Speed*Time Speed=Distance/Time Time=Distance/Speed
2.Convertion of Speeds:
KMPH To MPS(Kilometre per Hour TO Metres per Hour):
1 kmph = 5/18mps MPS To KMPH(Metres per Hour To Kilometre per Hour) 1mps=18/5kmph
If a train has to cross a man or any particular point then it has to cover a distance equal to its own length. If a train has to cross a bridge or tunnel or platform etc.
then it has to cover a length equal to its length + platform/tunnel length.
When two speeds are in opposite direction, Relative speed = sum of the speeds.
When two speeds in the same direction, Relative speed = difference of the speeds.
5.BOATS AND STREAMS:
Still Water: water without motion.A boat can traveL in that water with their original speeds.
STREAM / CURRENT : Water flow with some speed.
Down stream: along with the flow.
Upstream: against the water flow. If the speed of the boat in still water is b kmph and speed of the current is c kmph respctively,
then Downrate(*) = b+c
Uprate (y) = b-c
Speed of the boat (b) = x+y/2
Speed of the current = x-y/2
Average Speed =Total Distance/Total Time When two equal distance are covered at two different speeds (x,y),
then the average speed is =2xy/x+yKm/hr.
When three equal distance are covered at three different speeds (x,y,z),
then the average speed is = 3xyz/xy+yz+zx