• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5

# Dropping ball-bearing of various diameters into a viscous liquid, glycerol, timing the fall between two markers that are a known distance apart.

Extracts from this document...

Introduction

Asheeth Govindia

02/05/2007

Physics : Data Analysis

Aim

In this experiment I dropped ball-bearing of various diameters into a viscous liquid, glycerol, timing the fall between two markers that are a known distance apart.

I will then be looking for a relationship between the velocity of descent and the diameter.

Diagram

Method

1. I measured the diameter of the ball bearing.
2. I dropped a steel ball bearing down the pipe filled with glycerol.
3. As the ball bearing passed the first marker I started the stop clock.
4. As the ball bearing passed the second marker I stopped the stop clock.

Middle

2.18

9.55

3.19

3.22

3.2

9.61

10

3

3

3

3

4

14.1

14.02

14.09

14.07

Data Analysis

Stokes Law states that spheres falling through a fluid exhibit the following relationship.

Viscosity – any object moving through a viscous fluid is acted on by friction due to the fluid.  A higher viscosity will increase this friction that opposes its motion.

Calculating Viscosity

The force needed to separate molecules of the fluid according to Stokes is

Eq. (1) -> F = 6(pi)Rnvc,

Where R is the radius of the sphere, n is the viscosity of the fluid, and vc is the velocity of the sphere through the infinite fluid. This force can be set equal to the gravitational force modified to account for the buoyant effect as follows

Eq. (2) -> 6 (pi) R n vc = 4/3 (pi) R3 (pS-pL) g,

Conclusion

Eq. (7) -> n = [2 g R2 (pS-pL) t] / [9L (1 + 2.4x) (1 + 1.65y)].

Viscosity of glycerol

2 x 9.8 x 0.0022 x (8.02 – 1.26) x 14.07 = 2.628 poise

9 x 0.515

Resultant Force = W – Fr – u

W = mg

W = 4/3πr3 x density of steel x g

u = 4/3πr3σg

At terminal velocity:

W – Fr – u = 0

Because there is therefore no acceleration

Conclusion

From my results I concluded that as the diameter of the ball increases the speed of the ball increases, but so does the drag. This means that the force pulling the ball the ball is greater than the frictional force pushing the ball upwards. So as the ball’s diameter increases the drag increased but still the speed at which it falls through the liquid increases.

Bibliography
 Page Topic Source 3 Stokes Law http://hyperphysics.phy-astr.gsu.edu 3 Calculating Viscosity http://www.cord.edu

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

# Related GCSE Forces and Motion essays

1. ## Bouncing Ball Experiment

101 104 101 3 170 100 100 98 99 99 2 160 95 96 95 97 94 3 150 91 90 89 93 90 4 140 82 85 86 86 84 4 130 81 82 81 79 81 3 120 76 77 75 77 78 3 110 72 77 73

2. ## The effect of the temperature on the viscosity of the syrup.

Wait until the temperature falls down to 450 and repeat the procedure as for the 500 16) Repeat the whole procedure for the following temperatures three times: 500, 450, 400, 350 , 300, 250 and 200 17) Now place the measuring cylinder into the freezer and remove it when the temperature reaches 50.

1. ## Measuring the Viscosity of Honey

The ball bearing will then be retrieved from the honey using a magnet dragged up the side of the tube and repositioned at the surface of the honey. This should be repeated five times to generate three readings at each distance, to allow averages to be taken and the extent of any anomalies to be reduced.

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

The tube was filled to five centimetres below the top, to avoid splashing, with glycerol. Five centimetres below the top of the glycerol was marked with an elastic band around the tube, to signify the point to start timing. Ten centimetres below that, another elastic band was placed to mark the point to stop timing.

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

taken for five various sized ball bearings to descend through engine oil. This allows me to investigate the affect of viscosity on the surface area of a ball bearing. The results are as follows. Ball bearing Time taken (s) to descend 1 metre through engine oil 1 2 3 Average

2. ## Investigation into the effect of temperature on viscosity

A stirring rod is also used to mix the honey and create a constant temperature throughout. Cooling the honey Ice is added to the water surrounding the measuring cylinder to cool the honey, again the honey is stirred to produce a constant temperature throughout the honey.

1. ## Squash Ball and Temperature Investigation

To have fairness in the testing of balls, I will use the same ball each time for any kind of testing ensuring that the material of the ball is not different giving accurate, reliable results. To be very fair, a different ball made of the same material should be used

2. ## Investigating the viscosity of liquids.

the subject): ? = 2r2 g (?steel - ?fluid) / 9v With this equation, we are now able to calculate the viscosity of glycerol using the falling ball viscometer. Aim: To investigate how temperature affects viscosity of a fluid. Prediction: It has been predicted that the viscosity of the fluid will increase at higher temperatures.

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