Question

At 1 P.M., 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 25 km/h. How fast is the distance between the ships changing at 5 P.M.? (Round your answer to one decimal place.

Answer 1

how fast is the distance changing...thats me calculus ;)

Answer 2

there is a 4hour difference, so our trianlge has to reflect that fact..

Answer 3

i keep getting 53.7

Answer 4

but its wrong

Answer 5

x^2 + y^2 = r^2

Dx 2x + Dy 2y = Dr 2r ; dicide the 2s

Dx x + Dy y = Dr r

Dr = Dx x + Dy y //r Dx =35; Dy =25.

lets find x, y and r :)

Answer 6

y = 25(4)

x = 35(4) +150

Answer 7

y did u miltiply by 4?

Answer 8

ooooo i c

Answer 9

r = sqrt(100^2 + 190^2)

Answer 10

4 hours right :)

Answer 11

i multiplied them by 5

Answer 12

ok dont tell me answer..i wanna c if i can get this

Answer 13

Dr = 35(100) + 25(190)
-----------------
sqrt(10000 + 190^2)............you might to close your eyes for this then :)

Answer 14

where did the 190 come from?

Answer 15

the 100 came from multipying the 25 by 100 right

Answer 16

150 + 4(35) = 150 + 140 = ...290.....

Answer 17

i mean 25 by 4

Answer 18

25(4) yes = 100

Answer 19

oo ok

Answer 20

see, its good to check my work; after all, im just an idiot an disguise ;)

Answer 21

so is it 49.7

Answer 22

dunno, I stopped the math cause you didnt wanna know lol

Answer 23

Dr = 35(290) + 25(100)
----------------- looks better to me eh
sqrt(10000 + 290^2)

Answer 24

10150 +2500 7650
------------ = ---------- = 24.91... is what I get
sqrt(94100) sqrt(94100)

Answer 25

i had to adjust for my own stupidity :)

Answer 26

it said it was wrong :(

Answer 27

..... well the Dr part is correct, double check the distances to be sure.

Answer 28

for last step i did it differently, i did (140+100)/290 *(35+25)

Answer 29

Dr = Dw w + Dn n //r lets call it north and west...

Answer 30

or e for east.... im going blind i tell ya..BLIND!!

Answer 31

Dr = De e + Dn n //r De = 35; Dn = 25

e = 150 + 4(35); n = 4(25)

e = 290; n = 100

Dr = 35(290) + 25(100) //r

r = sqrt(290^2 + 100^2) = sqrt(84100 + 10000)
= sqrt(94100)

Dr = 10150 + 2500 12650
------------- = -------
sqrt(94100) sqrt(94100)

Dr = 41.2378

Answer 32

that should be it :)

Answer 33

ok thank u!!

Answer 34

just hope its right :)

Answer 35

u really are a life saver!!

Answer 36

thanx ;)