Two cars start moving from the same point. One travels south at 60mi/h and the other travels west at 25mi/h. At what rate is the distance between the cars increasing two hours later?
1 Answer
Sep 22, 2015
78.1mi/hr
Explanation:
Car A travels south and car B travels west
taking the origin as the point where the cars begin
equation of car A = Y = -60t
equation of car B = X = -25t
Distance D = (X^2 + Y^2)^0.5
D = (2500tt + 3600tt)^0.5
D = (6100tt)^0.5
D = 78.1*t
rate of change of D
dD/dt = 78.1
the rate of change of distance between the cars is 78.1mi/h
