Experiments to compare the relative viscosities of different liquids involve timing the fall of an object through a cylinder of the liquid. This proves that the terminal velocity is directly proportional to the radius squared. I presume this is to stop air bubbles forming; this would have a significant effect on the experiment. Velocity was calculated by the equation below. Vertically, in the above illustration, the projectile's initial velocity equaled zero, since it was launched straight forward. On another note, what were the units of the viscosities you calculated.
As the marble passes the starting point, which was marked in the previous section, the person holding the stopwatch should start the stopwatch. 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. A number of methods are used to measure the viscosity of fluids. This is not conclusive since the glycerol water content is not known, but certainly is reassuring. This means the cylinder must be sufficiently long enough for this to occur.
The answer is yes —by using dimensions. Furthermore, to make the results as accurate as possible, we had the same students responsible for the stopwatch and dropping the balls as we were hoping that there would not be a huge change in reflexes. Then think of a 1-inch cube of potato. From these results I concluded that the ball bearings of radius 3. So, now it's time to race some marbles and see if common liquids in your home are thick or thin! I was not satisfied that enough care was taken when measuring the 0. These are typically based on one of three phenomena—a moving surface in contact with a fluid, an object moving through a fluid, and fluid flowing through a resistive component.
Viscosity seams an ideal area to look into, and with the experimental data I have it seems possible to work out a value for its coefficient. Densities of some common materials. In order to test for the experiment, the group were given free use of an environmental chamber at National Technical Services. Introduction In this piece of coursework, The subject of terminal velocity is going to be discussed, and a terminal velocity experiment will be performed. The diameter of a small steel ball bearing is measured with a micrometer and it is then released from just above the glycerol surface and allowed to fall through the fluid, the time for it to pass from the level of one band to that of the other being taken. We used a ball of radius 1.
This can easily be proved with Stokes law. Likewise, in medicine, doctors try to keep blood viscosity in the correct range. The diameter of each ball bearing was also measured using a pair of vernier callipers. The equation you used applies to the balls falling through an infinite ocean of the fluid. Common liquids around your house thankfully don't form mountain slopes though, so to measure their viscosities, you have to use some other method. In preliminary 3 , my variable was the change in height from where the ball was dropped from and I kept the type of ball and the amount of viscous liquid glycerol the same. The viscosity, or resistance to flow, goes way down as the temperature goes up.
If the ball diameter is on the same order as the cylinder diameter, the relationship you used will not be as accurate. Its properties will change if it is allowed to absorb water vapour from the atmosphere so it must be kept in a closed container. In my equation i converted:- Radius from mm to m. Liquid name Trial 1 time sec Trial 2 time sec Trial 3 time sec Trial 4 time sec Trial 5 time sec Average of times sec Example: Corn syrup Table 1. The Reynolds number Re is calculated by this formula. However it may not be accurate as the weight of the lead ball was about 1000g heavier than the brass and copper ball. Apparatus and materials Measuring cylinder or tall and fairly wide glass tube, 1,000 ml, with firm stopper Glycerine, heavy oil or liquid detergent Ball bearings approximately 3 mm and 1.
When you are ready to release the ball bearing, call your instructor over to witness your trial. The vertical height, h, of the ramp should be no less than 7 cm. If you don't know the diameter of your marbles, measure the diameter with a ruler, and then divide by 2 to get the radius. The viscosity coeffience should be similar? This reduces the occurrence of air bubbles, which will affect the motion of the ball bearings. Despite this, the experiment should be valued for inspiring thoughts about how we can take advantage of the different conditions of outer space now space travel is possible.
Results I have formatted a table with the data attained from the experiment described above, each row of data relates to a different steel ball bearing. Do you mind if i post my first result which i belive to be correct in proper tex so u can point out any mistakes if you can see any. My first prediction was that terminal velocity was proportional to radius squared. If the ball is dropping at a steady speed, this force should just balance the weight of the ball. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed. The final test of your measurements and computations will be to position a bull's-eye on the floor so that the ball lands in its center circle on the first attempt. If you are interested in combining biology, chemistry, and the knowledge that you are helping people, then a career as a food scientist or technologist could be a great choice for you! Teaching notes 1 You could use a more sophisticated timing system, but the point here is to demonstrate terminal velocity rather than to make precise measurements.
After completing 3 different trials, a second spindle was selected and the procedure repeated. Also, the stopwatch must be started as soon as the ball hits the glycerol to make it a fair test. Before I start my coursework, I will go through what velocity is and how it is different to speed. This preliminary would not be suitable to do as the results taken would be very inaccurate. As long as laminar or streamline flow exists then, the stress exerted on the liquid is directly proportional to the velocity gradient that causes it.