• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Calculating the viscosity of Glycerol.

Extracts from this document...

Introduction

AS PHYSICS INVESTIGATION

Calculating the viscosity of Glycerol

Introduction:

Viscosity is a measure of the resistance against the flow of a substance (fluid). The higher the viscosity of a fluid, the less easily it can flow. The viscosity of a fluid can be calculated by using Stroke’s Law, which relates the viscosity of a fluid to the viscous drag (opposing force) and velocity at which it is travelling. One method of calculating the viscous drag (also the method I will be using) is by subtracting the upthrust exerted by the fluid on an object (ball) from the weight of the object as it is dropped through the fluid, assuming that the object has reached it’s terminal velocity and therefore has equal forces acting on it.

Aim:

To observe and record the terminal velocities of different sized balls falling through Glycerol, and hence calculate the viscosity of Glycerol.

Variables:

The only variables that will be changed for us to gain a range of results will be the size of the balls.

...read more.

Middle

Apparatus:

  • Cylindrical tubing (blocked off at bottom)
  • Rubber bands/tape for marking start and stop distances
  • Metre ruler, stopwatches and micrometer
  • Glycerol and set of different sized balls (densities assumed to be the same and constant through the balls and fluid)
  • Measuring tube/flask and balance to obtain a volume and mass for the calculation of densities.

Hypothesis:

        For this investigation, I am not expecting to obtain perfect results as there are a number of errors that are likely to occur due to the limitations of our apparatus and judgement. For one, the times we obtain may not be absolutely correspond, as we our using our own eyesight and stopwatches to gain this measurement, and is therefore limited to the speed of our reaction. Also, it cannot be guaranteed that the balls we use have gained maximum velocity, although the results may show that there is very little variation in the times (especially with larger balls, as their mass and therefore weight will cause them to move faster). I am also predicting that the graph we plot of radius2

...read more.

Conclusion

Evaluation:

        There are many improvements that can be made to give more accurate results for this experiment, although most of the changes that could be made do not include much that is possible with the apparatus that was provided. However, if more accurate and precise apparatus were to be used to take measurements, it would not dramatically affect the results over the length of tubing that is suitable for the conditions we had to work under. The main reason as I suggested before, for our inconsistent results was due to the balls not having reached their terminal velocity. The only method of allowing these balls to reach their terminal velocity would be to let them fall for a larger distance before recording the time’s. This is one improvement that could significantly better the experiment, any others being new methods of measuring the densities and velocities more accurately, maybe by using an electronic speedometer.

...read more.

This student written piece of work is one of many that can be found in our GCSE Forces and Motion section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Forces and Motion essays

  1. An Investigation into the terminal velocity of steel ball bearings in Glycerol.

    the ball bearings with the magnet, I also removed a small amount of glycerol. Over several retrievals, a considerable amount of glycerol may have been removed. If the volume changes enough, then the final results will be too varied, as density of fluid is dependant on volume.

  2. EXPERIMENT TO DETERMINE THE VISCOSITY OF GLYCERINE.

    * The balls should be wetted with glycerine before it is used also to avoid air bubbles clinging to its surface. * They should be dropped carefully and the bottom of the tube should be fitted with a rubber bung so that it does not break on impact * Care should be taken to avoid errors as much as possible.

  1. The effect of the temperature on the viscosity of the syrup.

    Since the layers travel in different velocities, from zero at the wall to maximum at the centre, positioning the descent of the sphere in different places each time will affect the rate of increase in velocity due to the increase in temperature.

  2. Bouncing balls experiment.

    The different heights of bounces not only depend on the height that the ball is dropped from but also the type of ball. Factors such as size, weight and material can greatly affect the height of the bounce. Here is the order of the highest bounce of a ball to the lowest: 1.

  1. Practical investigation into Viscosity in liquids (Stokes Law).

    Time taken(s) for ball bearing to pass through distance measured 1 2 3 Average 0-20 1.89 1.86 1.88 1.877 10-30. 1.83 1.77 1.80 1.800 20-40 1.76 1.75 1.78 1.763 30-50 1.76 1.79 1.77 1.773 40-60 1.77 1.78 1.77 1.773 Small Distance Timed (cm)

  2. Bouncing balls.

    h(mean) h(max) h(min) 2 1.1 1.1 1.11 1.09 1.12 1.104 1.12 1.09 1.8 1 1.01 1.01 1.02 1.03 1.014 1.03 1 1.6 0.91 0.91 0.9 0.9 0.89 0.902 0.91 0.89 1.4 0.79 0.77 0.78 0.78 0.78 0.78 0.79 0.77 1.2 0.68 0.7 0.68 0.67 0.69 0.684 0.7 0.67 1

  1. Viscosity of Fluids

    To do this I will use a falling ball viscometer. Before I carry out my experiment to determine the viscosity of honey at specific temperatures I need to consider the following variables: 1) Sphere radius: I will use the same ball bearing during this experiment so that it has the

  2. Practical Investigation Into Viscosity

    = 1000 cP P = 0.1Pl 1 centi-Poise (cP) = .01 poise Some examples of Viscosity - these may help you get a feel for the cP Hydrogen @20�C 0.008 6 cP Benzyl ether @ 20�C 5.33 cP Ammonia @ 20�C 0.009 82 cP Glycol @ 20�C 19.9 cP Water vapor @100�C 0.125 5 Soya bean oil @ 20�C

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work