Raising the Titanic
To raise the Titanic, an ocean liner that displaced 4.6*810^8 N of water when afloat. it was proposed to fill the inside of the sunken ship with ping-pong balls. A ping-pong ball has a diameter of 4.0 cm. The density of seawater is 1.025*10^3 kg/m^3. How many balls would it have taken to raise the ship?
I feel like we don't have enough information for this problem. Don't we need the volume as well?
Answer
You know that the buoyant force is equal to the weight of the fluid displaced. You also know that for the ship the float, its weight must be cancelled out by this buoyant force. The weight of water displaced is given in the problem, so you know the force that the ping-pong balls must provide.
You can find the volume of a ping-pong ball by treating it as a sphere with the given radius, and then you can find the mass of water displaced by one ping-pong ball using the density of seawater given.
m = ρ V
From the mass you can find the weight of water displaced by a single ping-pong ball, and then find the number of ping-pong balls required to raise the ship.
Customer support service by UserEcho
You know that the buoyant force is equal to the weight of the fluid displaced. You also know that for the ship the float, its weight must be cancelled out by this buoyant force. The weight of water displaced is given in the problem, so you know the force that the ping-pong balls must provide.
You can find the volume of a ping-pong ball by treating it as a sphere with the given radius, and then you can find the mass of water displaced by one ping-pong ball using the density of seawater given.
m = ρ V
From the mass you can find the weight of water displaced by a single ping-pong ball, and then find the number of ping-pong balls required to raise the ship.