Suppose oil spills from a ruptured tanker and spreads in a circular pattern. If the radius of the oil spill increases at a constant rate of 1.5 m/s, how fast is the area of the spill increasing when the radius is 30 m?

Respuesta :

Answer:

The area of the oil spill is increasing at a rate 180 π m²/s, when the radius is 30 m.

Step-by-step explanation:

Derivative Rule:

  • [tex]\frac{d}{dx}x^n=nx^{n-1}[/tex]
  • [tex]\frac{d}{dx}(y^n)=ny^{n-1}\frac{dy}{dx}[/tex]

Given that

The radius of the oil spill increases at a rate 1.5 m/s.

i.e [tex]\frac{dr}{dt}= 1.5\ m/s[/tex]

We need to find the rate of area increase i.e [tex]\frac{dA}{dt}[/tex] .

We know,

The area of the oil spills A = [tex]\pi r^2[/tex]  ( since it spreads in circular pattern)

[tex]\therefore A=\pi r^2[/tex]

Differentiating with respect to t

[tex]\frac{dA}{dt}=\pi. 2r\frac{dr}{dt}[/tex]

Plug the value of [tex]\frac{dr}{dt} =1.5 \ m/s[/tex]

[tex]\frac{dA}{dt}=\pi. 2r(3\ m/s)[/tex]

[tex]\Rightarrow \frac{dA}{dt}=6\pi r \ m/s[/tex]

Plug r= 30 m

[tex]\Rightarrow \frac{dA}{dt}=6\pi (30\ m) \ m/s[/tex]

         =180 π m²/s

The area of the oil spill is increasing at a rate 180 π m²/s, when the radius is 30 m.