Determine the Velocity of the body with Velocity decreasing by v^2 = k/s

[Northbysouth]

Homework Statement

A retarding force is applied to a body moving in a straight line so that, during an interval of its motion, its speed v decreases with increased position s according to the relation v²=k/s, where k is a constant. If the body has a forward speed of 1.8 in/sec and its position coordinate is 9.2 in at time t=0, determine the speed v at t=4.0 sec.

Homework Equations

v = ds/dt

The Attempt at a Solution

I'm honestly not sure how to start this question. Suggestions would be appreciated.

 

[rude man]

I would start with v = √(k/s) = ds/dt. k is easily gotten. Then get s(t) with the known boundary value, and finally substitute v = √(k/[s(t=4)].

Hope that puts you on the right track.