A man can swim at a speed of `5km//h` in the still water. He wants to cross a `1600m` wide river flowing at `4 km//h`. He keeps himself at an angle `127^(@)` with the river flow while swimming. (a) Find the time he takes to cross the river. (b) Find the distance traveled by him along the flow.

Explanation

`(v_(m//g))_(x)=5sin 37^(@)-4=3-4=-1 km//h`
`(v_(m//g))_(y)=5 cos 37^(@)=4 km//h`

`y: 1.6=4t implies t=0.4h =0.4xx60=24 min`
`x:x=1xxt=1xx0.4=0.4 km=400m`