A cylindrical water tank is 70cm in diameter. To begin with,it is full of water. A leak starts in the bottom so that it loses 10litre of the water every hour. How long will it take for the water level to fall by 20cm

Answer 1

Volume of cylinder = π(r^2)(h)

change of volume = π(35^2)(20) cm^3
= 24500π cm^3
= 24.5π L

At a rate of 10 L/h,
time = 24.5π/10 hours
= 2.45π hrs or appr 7.697 hrs or 7 hours and 42 minutes