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A boat is pulled into a dock by a rope attached to the bow of the boat and passing through a pulley on the dock that is 1 m higher than the bow of the boat. If the rope is pulled in at a rate of 1 m/s, how fast is the boat approaching the dock when it is 5 m from the dock? (Round your answer to two decimal places.)

Respuesta :

Answer:

1.0198m/s

Explanation:

let the distance of boat from the dock be [tex]x[/tex], then use Pythagorean theorem we have [tex]x^2+1^2=y^2[/tex]: where [tex]y[/tex] the length of the rope:

#Differentiate through with respect to [tex]t[/tex]

[tex]2x.\frac{dx}{dt}=2y.\frac{dy}{dt}[/tex]

Finding [tex]\frac{dx}{dt}[/tex], and [tex]\frac{dy}{dt}[/tex] is given as [tex]1ms^-^1[/tex]

With [tex]x=5m[/tex] at the given instant and [tex]y=\sqrt{26}[/tex]

Hence

[tex]5.\frac{dx}{dt}=\sqrt{5^2+1^2}=\sqrt{26}[/tex]

Rate of decrease of the distance between dock and boat is [tex]\frac{\sqrt 26}{5}[/tex]=1.0198m/s