Solving Statement For Upstream And Downstream


 
 
Concept Explanation
 

Solving Statement For Upstream And Downstream

Solving Statements For Upstream and Downstream: In these type of situations, while calculating upstream speed we subtract the speed of river from the speed of boat because the river is pushing the boat downwards even when the boat is moving upwards. Whereas when the boat is moving downstream the speed is calculated by adding the speed of river to the speed of boat.

Example: A boat goes downstream from one point to another in 9 hours. It covers the same distance upstream in 10 hours. If the speed of the stream is 1 km/hr. Calculate the speed of boat in still water.

Solution:     Let the speed of boat in still water be x km/hr

                    Speed of stream  = 1 km/hr

                    Speed upstream = x-1 km/hr

                    Speed Downstream = x + 1 km/hr

                    large speed= frac{distance}{time}

large distance= speed; X ;time

Distance upstream = (x-1) X 10 = 10x - 10 Km

Distance Downstream = (x+1) X 9 = 9x + 9 Km

According to the question the distance is the same

                          10x-10 = 9x + 9

                          10x - 9x = 9+ 10

                                    x = 19 km/hr

So the speed of boat in still watre = 19 km/hr.

Sample Questions
(More Questions for each concept available in Login)
Question : 1

The ship left the harbor and is travelling 60 kilometers downstream. Then it continues on the tributary river (upstream) 20 kilometers. Travel took 77 hours to finish. River speed is 11 km/h. Calculate the speed of a ship.

Right Option : B
View Explanation
Explanation
Question : 2

The current of a stream runs at 1 km/h. A motorboat goes 35 km upstream and back again at the starting point in 12 h. What is the speed of motorboat in still water ?

Right Option : C
View Explanation
Explanation
Question : 3

A person can row 7frac{1}{2} km/h in still water. It takes him twice as long to row up a distance as to row down the same distance. Find the speed of the stream.

Right Option : C
View Explanation
Explanation
 
Video Link - Have a look !!!
 
Language - English
 
 
 
 
Related Videos
Language - English



Students / Parents Reviews [20]