At noon, ship A is 50 nautical miles due west of ship B. Ship A is sailing west at 16 knots and ship B is sailing north at 24 knots. How fast (in knots) is the distance between the ships changing at 7 PM? (Note: 1 knot is a speed of 1 nautical mile per hour.)

answer with explanation please because I got the formula wrong. Thanks

1 answer

I did almost the same question yesterday ....

After the initial definitions, I would get:

d^2 = (50+16t)^2 + (24t)^2
at 7 pm, t = 7
d^2 = 26244+54468
d = 284.099

2d dd/dt = 2(50+16t)(16) + 2(24t)(24)
dd/dt = ((50+16t)(16) + (24t)(24) )/d

sub in t = 7 and d = 284.099 and find dd/dt