A cubic solid of plastic floats in water with 2/3 of its volume below the water line. What is the density? If the total volume of the block in the above question is 6.4 * 10^-5 m^3 what is the buoyant force on it?

the weight of the displaced water is more than the weight of the cubic solid of plastic

To find the density of the plastic, we need to determine the mass of the object. The density of an object can be calculated using the formula:

Density = Mass / Volume

Since 2/3 of the volume is submerged below the water line, the volume of water displaced is equal to 2/3 of the total volume. The buoyant force acting on the object will be equal to the weight of the water displaced, and this force can be calculated using the formula:

Buoyant Force = Density of Water * Volume of Water Displaced * Acceleration due to Gravity

The density of water is approximately 1000 kg/m^3, and the acceleration due to gravity is 9.8 m/s^2.

Now, let's calculate the density of the plastic:

Density = Mass / Volume

Knowing the volume and that 2/3 is submerged, we can calculate the volume of water displaced:

Volume of Water Displaced = (2/3) * Total Volume

Substituting the values into the formula for the buoyant force:

Buoyant Force = Density of Water * Volume of Water Displaced * Acceleration due to Gravity

Now we have the information to answer the questions.