An oil tanker aground on a reef is losing oil and producing an oil slick that is radiating out at a rate approximated by the function dr/dt , where r is the radius of the circular
slick in metres after t minutes. If the radius of the slick is 21 metres, after 15 seconds, find,
to the nearest metre, the radius of the slick after 10 minutes.

Question

An oil tanker aground on a reef is losing oil and producing an oil slick that is radiating out at a rate approximated by the function dr/dt , where r is the radius of the circular 
slick in metres after t minutes. If the radius of the slick is 21 metres, after 15 seconds, find, 
to the nearest metre, the radius of the slick after 10 minutes.

anonymous · Answer

$$dr/dt = 20/\sqrt{t}$$
when $$t \ge1$$
and r is the radios after t mins