MHT CET202210 Aug 2022Morning ShiftMathematicsApplication of DerivativesActual
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 ~cm ^3 / min . When the thickness of ice is 5 ~cm , then the rate at which the thickness of ice decreases, is
Options
- A1 36 cm / min
- B5 6 cm / min
- C1 54 cm / min
- D1 18 cm / min
Correct answer
D. 1 18 cm / min
Step-by-step solution
aligned & V= 4 3 r^3 & d v ~d t =4 r^2 d r ~d t & 50=4 15^2 d r ~d t & d r ~d t = 50 4 15^2 = 1 18 cm / min aligned