• 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. Bouncing balls.

    near the ruler, and then release it from rest without spinning at the top of the ruler, also I will drop the ball on the same vertical point as soon as possible, then observe the height after first bouncing by eyes carefully, our sight should be horizontal to the first bounce height.

  2. Bouncing balls experiment.

    The elastic potential energy stored in the ball when it has lost all its kinetic energy is converted back into kinetic and gravitational potential energy. The thermal energy however is converted back.

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

    Hence it will also affect the viscosity of the syrup. Temperature of the syrup - When the temperature is altered, the speed at which the molecule travels also changes. In effect the viscosity of the syrup also changes. Preliminary work To have an idea of the effect of different temperatures on syrup I will carry out preliminary work.

  2. 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.

  1. Investigation into the effect of temperature on viscosity

    ?v = 2 r� ?steel g -2 r� ?fluid g and cancel common factors 9 ?v= 2 r� (? steel - ?fluid)g divide by 9v ?= 2 r� (? steel - ?fluid) g substitute v for s/t (v=s/t) 9v ? = 2 r2 (? steel - ?fluid) g 9 (s/t)

  2. 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 0.45 0.49 0.46 0.467 10-30. 0.38 0.37 0.39 0.380 20-40 0.39 0.36 0.38 0.377 30-50 0.39 0.38 0.36 0.377 40-60 0.37 0.38 0.37 0.373 Large Distance Timed (cm)

  1. Practical Investigation Into Viscosity

    986 cP Liquid air @ -192.3�C 0.173 cP Glycerin @ 20�C 1,490 cP Ether @ 20�C 0.233 cP Pancake syrup @ 20�C 2,500 cP Water @ 99�C 0.2848 cP Honey @ 20�C 10,000 cP Chloroform@ 20�C 0.58 cP Chocolate syrup @ 20�C 25,000 cP Methyl alcohol@ 20�C 0.597 cP Ketchup

  2. Squash Ball and Temperature Investigation

    using a metre rule. Results Height of Bounce (cm) Height of Drop (cm) 1 2 3 4 5 Average (cm) Range (cm) 40 12 11 12 13 13 12 2 50 17 16 17 18 18 17 2 60 21 21 19 19 19 20 2 70 22 21 21 22 22 22 1 80 26 25 25 26

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