a women is walking at a rate of 6 ft/sec across a bridge 40 ft above the water, a man in a boat is immediately below the woman on the bridge , at right angles to the bridge and at the rate of 4 ft /sec. how fast is the man and woman seprating at the end of 10 seconds(adsbygoogle = window.adsbygoogle || []).push({});

what i have figured out is the 2 deminationally not including the 40 ft

dx/dt = 6ft/sec dy/dt = 4 ft/sec dz/dt = ?

z^2 = x^2 + y^2 z = sq root 52 = 7.21

using implicate differenating dz/dt = 1/z (x(dx/dt) + y(dy/dt))

dz/dt = 1/7.21(4(10) +6(10)

= 100 / 7.21

= 13.87 ft/sec

I can drw it diagram but not sure what to do for the 40 ft

thanks joe

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