Question

Styrofoam has a density of 32kg/m3.

Part A What is the maximum mass that can hang without sinking from a 20-cm diameter Styrofoam sphere in water? Assume the volume of the mass is negligible compared to that of the sphere. Express your answer with the appropriate units.

Answer 1

Find the volume of the balls
V = 4/3 * pi * r^3
r = 10 cm = 0.10 m

V = 0.00418 m^3

Find the mass of the water that is associated with a volume of 0.0446 m^3
m = ??
V = 0.00418 m^3
d = 1000 kg/m^3

m = V * d
m = 0.00418 * 1000 = 4.18 kg
And then
find the mass of the styrofoam ball.
V = 0.00418 m^3
d = 32 kg / m^3
m = 0.00418 * 32
m = 0.1337 kg

find the mass needed to put on top of the ball.
The difference is what you are going to have to put on the ball.
4.18 - 0.1337 = 4.046 kg ans.