Question

select the correct answer.
the current in a river is 1.0 meters/second. britney swims 300 meters against the current. if she normally swims with a speed of 2.0 meters/second in still water, how long does it take her to complete the trip?
a. 100 seconds
b. 200 seconds
c. 400 seconds
d. 300 seconds

Explanation:

Step1: Calculate effective speed

$v_{\text{eff}} = v_{\text{still}} - v_{\text{current}} = 2.0 - 1.0 = 1.0 \, \text{m/s}$

Step2: Calculate time

$t = \frac{d}{v_{\text{eff}}} = \frac{300}{1.0} = 300 \, \text{seconds}$

Answer:

D. 300 seconds