3ft/s. How rapidly is the area enclosed by the ripple increasing at the end of 10s?
2007-10-02 14:14:56 · 2 answers · asked by Deutschjoe 3 in Science & Mathematics ➔ Mathematics
Start with the equation for the area of a circle. find dA/dt (hint: r is not a constant, it depends on t. Use the chain rule).
dr/dt is the rate the radius changes with time which was given in the problem. Substitute this in your derivative.
2007-10-02 14:21:47 · answer #1 · answered by Demiurge42 7 · 0⤊ 0⤋
Area_Circle = &pi*r²
every three seconds the r is increasing by 3feet
Because we are dealing with a "rate" ( IE how 'rapidly'...) we do not need to know the initial ripple size (or the size of the stone, same thing basically) ... we just want to know how many ft/s is it increasing by
2007-10-02 21:19:43 · answer #2 · answered by David F 5 · 0⤊ 0⤋