MHT CET20226 Aug 2022Evening ShiftMathematicsApplication of DerivativesActual
A spherical iron ball of 10 ~cm radius is coated with a layer of ice of uniform thickness that melts at the rate of 50 ~cm ^3 / min . If the thickness of ice is 5 ~cm , then the rate at which the thickness of ice decrease is
Options
- A1 18 cm / min
- B2 9 cm / min
- C-1 18 cm / min
- D1 3 cm / min
Correct answer
A. 1 18 cm / min
Step-by-step solution
aligned & v= 4 3 r^3 & d v d t =50 r=(10+5)=15 ~cm & d v d t =4 r^2 d r d t & 50=4 15 15 d r d t & d r d t = 50 4 15 15 = 1 18 cm / min aligned