1,000 identical drops of oil of density 5000kg/m have
a total mass of 5 x 10kg. one of the drops forms a thin
film of area 0.5m2
on water. The thickness of the film
is?
volume = area * thickness
5*10kg * 1m^3/5000kg = 0.01 m^3
0.01m^3 = 1000*0.5 m^2 * thickness
2*10^-5m = thickness
To find the thickness of the oil film, we need to use the formula for density, which is mass per unit volume. In this case, the total mass of the oil is 5 x 10 kg and the density of the oil is 5000 kg/m^3.
First, let's determine the volume of the oil. We know that the total mass of the oil is the sum of the masses of each individual drop, so we can divide the total mass by the number of drops to find the mass of each drop:
Mass of each drop = Total mass / Number of drops
Mass of each drop = 5 x 10 kg / 1000 drops
Mass of each drop = 0.005 kg
Next, we can find the volume of each drop using the formula for density:
Density = Mass / Volume
Rearranging the formula, we can solve for volume:
Volume = Mass / Density
Volume of each drop = 0.005 kg / 5000 kg/m^3
Volume of each drop = 1 x 10^-6 m^3
Now, we can find the thickness of the oil film by dividing the volume of each drop by the area of the film:
Thickness = Volume / Area
Thickness = (1 x 10^-6 m^3) / 0.5 m^2
Thickness = 2 x 10^-6 meters or 2 micrometers
Therefore, the thickness of the oil film is 2 micrometers.