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

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...


Asheeth Govindia


Physics : Data Analysis


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.



  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.
...read more.


















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,

...read more.


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


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.






Stokes Law



Calculating Viscosity


...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 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.

  2. Investigation into the effect of temperature on viscosity

    If the ball was dropped through the air and into the honey it could accelerate past its terminal velocity (in honey), meaning it would be travelling faster than it should as it moved through the honey. Therefore the ball is dropped from the surface of the honey with its initial velocity equalling 0ms-1 5)

  1. Practical Investigation Into Viscosity

    When Re is low, laminar flow dominates and drag is approximately equal to speed X size X dynamic viscosity giving a linear rise in drag with speed (and a squaring of power with speed). On the other hand, when Re is large drag is approximately equal to Speed2 X Size2 X density!

  2. This investigation is associated with the bounce of a squash ball. I will be ...

    remains the same; - P = F A However the 3 different balls will obey this law but will differ in bounce height at the different temperatures and also will show different gradients in the area of proportionality in the graph as shown on the graphs.

  1. Squash Ball and Temperature Investigation

    poor insulators as they will not loose the heat energy as quickly. c) Some materials may have a molecular structure that allows a lot of space for air molecules which would result in an increase of air pressure within the ball affecting its bounce back height (the higher the air pressure, the higher the bounce back height).

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

    Drop the sphere inside the syrup as well as starting the stop watch 11) Stop the stop watch as soon as the sphere crosses the line that is marked on the beaker 12) Record the time 13) Wait until the temperature falls down to 700 14)

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

    This enabled me to investigate the surface area, mass* and how this effected the rate of descent. The results of experiment 1 are as follows: Very Small Distance Timed (cm) Time taken(s) for ball bearing to pass through distance measured 1 2 3 Average 0-20 0.19 0.21 0.20 0.200 10-30.

  2. Bouncing Ball Experiment

    The ball starts at height h1. GPE = m � h1 � g * Energy ball starts with = mh1g * No energy is lost when the ball is falling; there is no air resistance, so no Thermal Energy is produced.

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