the distance z between the ships after t hours, is given by
z^2 = (150-35t)^2 + (30t)^2
at t=4, z=30√5
So, plug in your values, using
2z dz/dt = -70(150-35t) + 1800t
At noon, ship A is 150 km west of ship B. Ship A is sailing east at 35 km/h and ship B is sailing north at 30 km/h. How fast is the distance between the ships changing at 4:00 PM?
2 answers
where does the -70 come from?