Question

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 19 m?

Answer 1

A = pi*r^2
dA/dt = 2pi*r

Answer 2

so 2(pi)(19)^2?

Answer 3

No wait i forgot the dr/dt

Answer 4

dA/dt = 2pi*r*(dr/dt)
= 2pi*19(m)*1.5(m/s)

Answer 5

dA/dt = 57pi (m^2/s)

Answer 6

As you can see, the units work out nicely :)

Answer 7

yep, can you help me with this one too
Each side of a square is increasing at a rate of 9cm/s. At what rate is the area of the square increasing when the area of the square is 36cm2.

Answer 8

sorry im late for college.. all right last one..

Answer 9

A = 36cm^2 => side = 6 cm

Answer 10

A = side^2
dA/dt = 2*s*ds/dt = 2*6cm*9(cm/s) = 108cm^2/s

Answer 11

when will you be on again. thanks for the help

Answer 12

no clue.. but email me if anything

Answer 13

oh what is your email?

Answer 14

did u get it?

Answer 15

it popped up on my screen, how do i go to it?

Answer 16

click notifications

Answer 17

ok ok i got it

Answer 18

thanks once again. hope you have a good day

Answer 19

np, u too