Question

A swimmer's speed along the river is 20 km/hr and up stream is 8 km/hr . Calculate the velocity of the stream and the swimmer's possible speed in still water

Answer 1

Answer:

Velocity of the stream = 6 km/h and the velocity of the swimmer in still water is = 14 km/h.

Explanation:

Step 1 : Let the speed of the swimmer in still water be x and that of the stream be y.

Step 2 : Write down the formula for the speed upstream and downstream.

Speed upstream = speed in still water - Speed of the stream.

Speed downstream = Speed in still water + Speed of the stream.

Step 3 : Form 2 equations from the given information.

x - y = 8

x + y = 20

Step 4: Solve the equations simultaneously.

x - y = 8

x + y = 20

Add the two equations to get :

2x = 28

x = 28/2

x = 14 km/h

Substitute to get y.

14 - y = 8

-y = 8 - 14

-y = - 6

y = 6 km/h

The velocity of the stream is 6 km/h

The velocity of the swimmer in still water is 14 km/h

Answer 2

Answer:4 km/hr

Explanation:

a swimmers speed in the direction of flow of river is 16km/hr .Against the direction of flow of river, the swimmers speed is 8km/hr .calculate the swimmers speed in still water and the velocity of flow of the river.

let x=swimmers speed in still water

let c=velocity of flow of the river.

..

x+c=16

x-c=8

 

add

2x=24

x=12

c=16-x

c=4

swimmers speed in still water=12 km/hr

velocity of flow of the river=4 km/hr