Stokes law applies to a fluid of an infinite extent, but in this investigation we are using a cylinder. As the marble passes the ending point, which was marked in the previous section, the person holding the stopwatch should stop it. A very thin and fluid magma erupts more easily and forms gentle mountain slopes, while a very thick magma erupts explosively and forms a fat lava flow and steep mountain slopes. Bearing in mind that it drops by 10% for each one-degree rise in temperature, most likely it was not at a uniform temperature, or our measurement of temperature was inaccurate. Experiment To Find The Terminal Velocity Of A Ball Travelling In Glycerol Essay While the free essays can give you inspiration for writing, they cannot be used 'as is' because they will not meet your assignment's requirements.
Since we think our measurements of radius, mass and speed were fairly accurate, the viscosity was evidently less than we thought. Measuring Liquid Viscosity A rotational viscometer uses the principle behind the ideal model of shear stress being produced between a stationary plate and a moving one under non-slip conditions. This could easily account for the difference. This graph clearly shows a straight trend line that passes through the origin. This is because the number I am receiving from the sum is raising in line with the radius of the sphere.
Hence, the time taken is less for a bigger ball bearing than for a smaller one. Likewise, in highly viscous liquids those with high internal friction , the resistance to flow is high. After completing 3 different trials, a second spindle was selected and the procedure repeated. As the temperature goes down, the viscosity, or resistance to flow, goes way up and you can squeeze and squeeze all you want, but very little honey comes out. The data collected was: Time taken to move 0.
In an otherwise darkened room full blackout is not necessary the ball-bearings then appear as bright points of light. This velocity at the base of the incline will remain the ball bearing's horizontal velocity when it leaves the table. Now, I will go through how I will do my experiment. First, the viscometer had to be leveled, centered within the beaker, and the auto-zeroing function run to completion. The graph shows that there is an inverse relationship between the time taken and the diameter of the steel ball. It follows that for two balls of the same density ρ , after canceling a from each side, the ratio of their terminal velocities is the square of the ratio of their radii, a ball with radius 2 a will fall four times faster than a ball with radius a. The process of the numerical program is: 1 Set the parameters of material and geometry; 2 calculate the distance of y from Eq.
The problems of the stopwatch and the use of are probably the biggest factor sin causing uncertainties and inaccurate results. The viscosity is a property of the liquid, and is independent of the objects that are used. Moreover, it is difficult to determine where the falling ball arrives at the terminal velocity, i. A tall glass tube allows a greater distance of fall than a measuring cylinder. But this did not prevent me from making suitable analysis. I will now plot a graph to make the relationship between the diameter of the ball bearings and the time taken to travel a distance of 162mm.
There are problems with the photodiode setup, and would require the ball bearing to be accurately dropped from a specific position. This does not give a definitive answer but certainly a more appropriate one. Corrections I have identified possible problems in the initial evaluation, however these can be partially be overcome using mathematical corrections. Common liquids around your house thankfully don't form mountain slopes though, so to measure their viscosities, you have to use some other method. This brings me to belive the higher mass caused a slower acceleration not allowing them to reach terminal velocity in 20cm thus distorting the results? I am going to look into it with slightly more detail. Moreover, six balls were used with different diameters for various dynamic viscosity measurement ranges, and a suitable ball can be selected when the fall times of the ball are not lower than the minimum fall times recorded during a testing procedure. This solution would also help reduce the effect the wall boundaries have on the viscosity, as I have shown using the Ladenburg corrections — these have quite a significant effect.
The top balance may have created problems too, but as before these too would be universal they also would not effect the experiment. The readings that were taken were used to calculate average time taken and average speeds for this experiment. Objective To determine the viscosity of common liquids by measuring the transit time of marbles through the liquids. Seal the bottom end firmly with a stopper and rest this on a surface so that it cannot fall out. On dropping it through the glycerin, and allowing some distance for it to reach a steady speed, we found it fell 25cm. Figure 1 depicts the drag coefficient versus Reynolds number with the experimental results and two curve-fitting lines.
For example, a small object like a raindrop, would have a low terminal velocity, and would only accelerate over a short distance before air resistance equals its weight. If you set the honey bear in a pan of warm water for a few minutes and try again, what happens? First we must ask: what can this drag force depend on? To make it a fair experiment, the ball must be dropped from the same height each time it is dropped into the glycerol. The inertial effects of this turbulence however can be accounted for. Prediction I predict that as the ball falls through the glycerol, it will slowly start to slow down in acceleration due to air resistance. When this happens, the resultant force, is zero because of the opposing forces being balanced. Nicholas Metzgen Physics A2 Coursework — An Investigation into the terminal velocity of steel ball bearings in Glycerol Hypothesis In this experiment, I plan to investigate the relationship between velocity and viscosity, as this is something that has always interested me. I am not told what unit i am attempting to measure, I was simple given an experiment sheet with the Aim to:- Determine the coefficent of viscosity of glycerol.