Lisa rowed her boat for two miles downstream. The trip took her 20 minutes. She then turned around and rowed back
the two miles. It took her one hour to row back upstream.
a. At what rate of speed did Lisa row downstream?
b. At what rate of speed did Lisa row upstream?
c.
Suppose Lisa’s speed rowing upstream was 4 miles per hour. How long would it have
taken her to travel two miles?
To find the rate of speed at which Lisa rowed downstream, we can divide the distance she traveled downstream by the time it took her to row that distance.
a. Rate of speed downstream = Distance traveled downstream / Time taken to row downstream
Distance traveled downstream = 2 miles
Time taken to row downstream = 20 minutes = 20/60 = 1/3 hour
Rate of speed downstream = 2 miles / (1/3) hour = 6 miles per hour
So, Lisa rowed at a speed of 6 miles per hour downstream.
To find the rate of speed at which Lisa rowed upstream, we can use a similar approach.
b. Rate of speed upstream = Distance traveled upstream / Time taken to row upstream
Distance traveled upstream = 2 miles
Time taken to row upstream = 1 hour
Rate of speed upstream = 2 miles / 1 hour = 2 miles per hour
So, Lisa rowed at a speed of 2 miles per hour upstream.
Now, let's consider the scenario where Lisa's speed rowing upstream was 4 miles per hour and calculate how long it would have taken her to travel two miles.
Let's use the equation:
Time = Distance / Speed
c. Time taken to travel two miles upstream = Distance traveled upstream / Rate of speed upstream
Distance traveled upstream = 2 miles
Rate of speed upstream = 4 miles per hour
Time taken to travel two miles upstream = 2 miles / 4 miles per hour = 0.5 hours = 30 minutes
So, if Lisa's speed rowing upstream was 4 miles per hour, it would have taken her 30 minutes to travel two miles.