How long will it take you to reach your friends?

Question

your friends are on the other side of the river that is 726 feet wide. the river has a current that flows due east at a speed of 1 foot per second. you are able to kayak at an average speed of 1.5 miles per hour. where should you launch your kayak to ensure you reach your friends in the least amount of time? how long will it take you to reach your friends, once you start kayaking?

Answer 1

How long will it take to go across the river?

1.5 mph = 7920/3600 ft/sec = 2.2 ft/ sec.

To go 726 ft will take 726/2.2 = 330 sec.

In 330 sec the current will take you east 330 ft; therefore, you need to start 330 ft west of where your friends are.