Problema Solution
mike likes to canoe. he can paddle 150 feet per minute. he is planning a river trip that will take him to a destination about 30,000 feet up stream (that is, against the current). the speed of the current will work against the speed he can paddle.
a. let s be the speed of the current in feet per minute. write an expression for r(s), the speed at which mike is moving relative to the river bank, in terms of s.
Answer provided by our tutors
The current is working against Mike’s paddling, pushing him back, so we subtract the speed of the current, s, from Mike’s paddling velocity, 150, to get how fast he is actually moving, r(s). So, with units of feet per minute, we have r(s)=150-s.