Answer to Question #337049 in Calculus for Kheyt

Question

Two jeepney leaves at the same terminal. Jeepney A heads North at a

constant speed of 40 ??/ℎ while jeepney B heads East at a constant

speed of 60 ??/ℎ. How fast is the distance between them changing

after 30 ?????

Answer 1

$a^2+b^2=c^2$

For 30 min=0.5 hour one goes 40x0.5=20 km, other 60x0.5=30 km. Si distance between them is $D=\sqrt{20^2+30^2}=36$ km

$dD/dt=36km/0.5 h=72 km/hour$