Donald Duck and his nephews manage to sink Uncle Scrooge's yacht (m = 3527 kg), which is made of steel (ρ = 7850 kg/m^3). In typical comic-book fashion, they decide to raise the yacht (which is now on the bottom of a lake) by filling it with ping-pong balls. A ping-pong ball has a mass of 2.70 g and a volume of 3.35·10-5 m^3.

Question

a) What is the buoyant force on one ping-pong ball in water?
b) How many balls are required to float the ship?

Answer 1

Mg = F – mg
Mg =N• •g - N•m•g <
where M = 3527 kg,
ρ = 1000 kg/m^3 – the density of water,
V =3.35•10^-5 m^3,
m =2.7•10^-3 kg
N =M/(ρ•V – m) =1.15•10^5

Answer 2

why is this a question