## Boats And Streams

### Introduction

DownStream:- In water, the direction along the stream is called downstream

UpStream:-  The direction against the stream is called upstream.

If the speed of a boat in still water is u $$\mathrm{km} / \mathrm{hr}$$ and the speed of the stream is $$\mathrm{v}\;\mathrm{km} / \mathrm{hr},$$  then:-

Speed downstream = $$(u+v) \mathrm{km} / \mathrm{hr}$$

Speed upstream = $$(u-v) \mathrm{km} / \mathrm{hr}$$

If the speed downstream is a $$\mathrm{km} / \mathrm{hr}$$ and the speed upstream is b $$\mathrm{km} / \mathrm{hr}$$  , then:-

Speed in still water = $$\frac{1}{2}(a+b) k m / h r$$

Rate of stream = $$\frac{1}{2}(a-b) k m / h r$$