In calm waters, the oil spilling from the ruptured hull of a grounded tanker spreads in all directions. Assuming that the polluted area is circular, determine how fast the area is increasing when the radius of the circle is 60 ft and is increasing at the rate of 1 2 ft/sec?

2260.8 ft ^ 2 / s

Step-by-step explanation:

To solve the problem we first know that:

dr / dt = 6 ft / s

r = 60 ft

Now they ask us for dA / dt, the change of the area with respect to time, by chain rule we have to:

dA / dt = dA / dr * dr / dt

we have that A = pi * r ^ 2

d (pi * r ^ 2) / dr

deriving the above we are left with:

 2 * pi * r

replacing:

dA / dt = (2 * pi * r) * 6

dA / dt = 2 * 3.14 * 60 * 6

dA / dt = 2260.8 ft ^ 2 / s

therefore the area change per second is 2260.8 ft ^ 2 / s

answer: the answer is one of

step-by-step explanation:   we are given to write a proper fraction where the whole is divided into an even number of equal parts less than ten, and an odd number of those parts exist.

an even number less than 10 may be one of 2, 4, 6 or 8. so, the whole may be one of these four evens.

now, an odd number of these parts must exist, so the numerator must be an odd number, one of 1, 3, 5 or 7. it cannot be 9 because then the fraction will become improper.

thus, our fraction may be one of the following

answer: i'm not going to give you the answer, but some hints to work it out.

step-by-step explanation: so, if there is a straight line that means that the line angle is 180°. so we subtract the 2 angle measures provided, (15 and 38) from 180. so the answer is 180 - (38 + 15). (you have to solve the equation)