448 algebra De mystif ieD
Totaltime Distancedownstream
Averagespeed s
=
+ ttream’sspeed
Distanceupstream
Averagespeed
+
−stream’s speed
• Solve falling object problems. If an object is dropped, thrust upward, or
thrown downward, its height t seconds after release, is ht=− ++^162 vt 00 h,
where v 0 is the object’s initial velocity (in feet per second); and h 0 , its
initial height (in feet). We are given enough information to eliminate all
variables except t and then we solve the equation for t.