12 Mathematics Applications of Derivatives - Set No : 26 Question No :9
Question No : 9
A
spherical iron ball 10 cm in radius is coated with a layer of ice of uniform
thickness that melts at a rate of 50  When the thickness of ice is 15 cm.
then the rate at which the thickness of ice decreases, is |
| a) |  cm/min | b) |  cm/min |
| c) |  cm/min | d) |  cm/min |
Answer No : 9
(c)Given
,    Hence
, the thickness of ice decrease by 1/18 cm/min |