I want to know why speed and time are used, to find the width of a river. Only length is needed.

https://forum.allaboutcircuits.com/threads/how-wide-is-the-river.148204/

 

I want to know why speed and time are used, to find the width of a river. Only length is needed.

https://forum.allaboutcircuits.com/threads/how-wide-is-the-river.148204/

Because the information that you have to work from involve where two boats meet within the river after starting from opposite sides at the same time. The width of the river is the sum of the distances traveled by the two boats. And here's the big secret that is needed -- the distance traveled depends on speed and time.