Report1

Date: 01/26/2007 To: Chang- Beom Park From: Hai Nguyen Re: Measurement of liquid densities and viscosities. Description of Measurement Technique : * Apparatus: - Three tubes of viscometers with different sizes( two size #3 and one size #1). Each of two size #3 either contains oil or water. The viscometer #1 contains water. - A thermometer( to measure the room temperature) - A calibrated cylinder - An electric scale -Oil and water * Procedure: In this experiment, we measured the viscosities of a variety of fluids such as water, alcohol and oil. In order to calculate the viscosities of a variety of fluids we have to apply the following formula: μ= K( ρs – ρ)t where K is a constant depending on size of the viscometer, ρs is the density of the ball, ρ is the density of water, and t is the elapsed time. In order to measure K for each viscometer, we measured the viscosity of water by the following formula: μ= A.10B/(T-C) where, A= 2.414x 10-5Ns/m2, B=247.8 K, C=140 K and T is the room temperature. Since that we will get

K= μ/( ρs – ρ)t.

For each fluid, we are going to make at least six trials of measurement in order to get the most satisfactory results. - Measure the density of each liquid: We take a sample of each liquid to measure the weight and volume of each one successively. Then, we will be able to derive the density from the formula: μ= mass/ volume

Result: *Densities: -For water: ρw= Vw/Mw= 0.774±0.020 g/ml -For the oil: ρo= 0.849± ± 0.019 g/ml *Viscosities: Find K: : K3= μ/( ρs – ρ)t=9.47x 10-4Ns/m2/[(2.53kg/m3-1 kg/m3)103.2.51s]=6.19x10-7 m2/s2 -For viscometer #1<steel ball>: K1= μ/( ρs – ρ)t=9.47x 10-4Ns/m2/[(8.02 kg/m3-1 kg/m3) 103x37.46s] = 3.601x10-9 m2/s2 Find Viscosities: -Apply formula: μ= K( ρs – ρ)t -For oil: μ= K( ρs – ρ)t= 6.19x10-7 m2/s2(8.02 -0.849)103. kg/m3x37.46s=0.1663±0.0016 ±0.0016 Ns/m2

*The uncertainty of oil viscosity: