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

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Related rates

**Physics Forums | Science Articles, Homework Help, Discussion**