A motorboat is moving at 20 m/s when the engine quits. Assume that the resistance is proportional to the velocity. Also assume that after 20 seconds the velocity is 10 m/s. How far does the boat coast?
I need help sorting the information out. What exactly does it mean for the boats engine to have quit while it's moving 20 m/s? What does that tell us? So far I have:
$\frac{dv}{dt}=-kv$
$v(20) = 10$
Where to go from here? How do I find $k$? What am I trying to "solve" to figure out how far the boat coasts?
Thank you!