A rectangular fish tank with a base of 100 cm × 50 cm contains water up to a height of 20 cm. If 5 identical spherical stones, each with a radius of 5 cm, are dropped into the tank and fully submerged, what is the rise in the water level?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. cm.
Base area of rectangle = 100 × 50 = 5000 cm2
Volume of 5 spheres = 5 × (4/3)πr3 = 5 × (4/3) × π × 53 = (2500π)/3 cm3
Length rise = (2500π/3) ÷ 5000 = π/6 cm