Immersed => totally submerged
a) Volume occupied by the ball, V = area of the base of the cylynder * water level rise
V =π(r^2)(4cm) = π*100cm^2*4cm = 400 π cm^3
Volume of a sphere = [4/3]π(r^3) = 400 π cm^3 =>
r^3 = 300 cm^3 => r = ∛(300 cm^3) = 6.69 cm
b) V = π(100cm)^2 (8cm) = 80,000 π cm^3
[4/3]πr^3 = 80,000π cm^3 => r^3 = 60,000 cm^3 => r = 39.15 cm