Boat traveling upstream and downstream equation

Question

A boat traveled downstream a distance of 136 mi. If the speed of the current was 7mph and the total trip took 5 hours and 40 minutes find the average speed of the boat relative to the water

Answer 1

The total boat speed =
(speed of the current) + (speed of the boat relative to current)

 

To do this problem, then, find the total speed of the boat. Then subtract the current speed to find the speed of the boat relative to the current.

 

Total speed = (Total distance traveled) / (Total time elapsed)

 

40 minutes = 2/3 hours because there are 60 minutes/hour

 

Total speed = (136 mi) / (5 and 2/3 hours)

 

Total speed = 24 miles/hr

 

Current speed = 7 miles/hr (per problem description)

 

Therefore, speed of the boat relative to current = 24 - 7 = 17 mph

Answer 2

Hi Ashanti,

 

Let's look at what the question is asking, as well as the information they've provided.

 

Our end goal is to find the average speed of the boat "relative" to the water. We're also told that the total distance is 136 miles while the total time taken is 5 hours and 40 minutes, with a current of 7 mph. First, we need to find a formula that relates distance, speed, and time. Then, keeping units in mind, we need to find the boat's speed in relation to the current's. 

 

Let me know if you make any progress!