A plastic sphere has a density that is greater than oil but less than water when itis placed in cylinder containing water, it is exactly half submerged, explain why when oil poured on top of water. The sphere is only 1/4 submerged in water.
The density of the sphere is 1/2 of the density of water. But when oil is added to the water, the resulting solution has a density twice that of water. So the new density ratio is 1/4.
To understand why the plastic sphere behaves differently when oil is poured on top of water, we need to consider the concept of density.
Density is a measure of how much mass is contained in a given volume of a substance. It is calculated by dividing the mass of an object by its volume. In this scenario, the density of the plastic sphere is somewhere between that of oil and water.
When the plastic sphere is placed in a cylinder containing water, it becomes partially submerged. The point at which it stops sinking and starts floating is determined by comparing the density of the sphere to the density of the liquid it is placed in. For an object to float, its average density must be less than the density of the liquid.
In this case, the density of the plastic sphere is greater than that of oil and less than that of water. Since oil has a lower density than water, the plastic sphere is able to displace less water and therefore floats higher in the oil compared to water.
When oil is poured on top of the water, two layers are formed due to the difference in density. Oil being less dense than water, floats on top. As a result, the plastic sphere floats higher in the oil layer than in the water layer because its density is closer to that of the oil.
In the water layer, the plastic sphere is only 1/4 submerged because the sphere's density is still greater than that of water, but it is closer to the water's density than the oil's. This causes it to sink deeper in the water compared to when it was only in water alone.
In summary, the plastic sphere behaves differently when oil is poured on top of water because the difference in density between the oil and water affects the buoyancy of the sphere differently in each liquid.