Saved Bookmarks
| 1. |
A boat which has a speed of 5 km per hour in still water crosses a river of width 1km along the shortest possible path in fifteen minutes. The velocity of the river water in km per hour is |
|
Answer» Answer: LET the velocity of the RIVER be x. the velocity of the river will be in the HORIZONTAL direction velocity of boat in still water is 5km/hr. As the width of the river is 1 km and time taken by the boat to cross the river along the shortest path is 15 min therefore the velocity of the boat is= 1*60/15= 4km/hr according to the figure the velocity of the river is along AB . By applying triangle law of vector addition the value of AB COMES to be 3km/hr |
|