A solution of known concentration of oleic acid in alcohol is prepared.
Let 1 cm3 of oleic acid be dissolved in 500 cm3 of
alcohol to get concentration. Let n drops of this solution be poured on a water surface contained in a flat and broad vessel. Oleic acid film is stretched on the water surface. After sometime, oleic acid is left behind, as alcohol gets evaporated. Area A of oleic acid is measured with the help of tracing paper and a graph. Let v be the volume of an oleic acid drop solution.
Let t be the thickness of oleic acid film of surface area A
If it is assumed that the oleic acid film is stretched so that its thickness is of one molecule, then the above equation, gives the diameter of one molecule of oleic acid.
RADAR which means 'Radio Detection And Ranging' is used to determine the distance of moon from earth. The method involved is reflection technique. To measure the distance of moon, a signal is sent from the radar and is received by the detector as a reflected signal. Let t be the time taken for the to and fro travel of radar signal and c be the velocity of the wave.
concentration. Let n drops of this solution be poured on a water surface contained in a flat and broad vessel. Oleic acid film is stretched on the water surface. After sometime, oleic acid is left behind, as alcohol gets evaporated. Area A of oleic acid is measured with the help of tracing paper and a graph. Let v be the volume of an oleic acid drop solution. 
