Physics Lab Sheet Topic: A2 - Forces and momentum
Grade: 11 IB-DP Name: Tamara
Lab: To estimate the viscosity of washing up liquid
Aim:
To estimate the viscosity of washing up liquid using the velocity of a ball falling through the
liquid.
Formula :
Fd = 6𝛑ηrv
Apparatus:
Measuring cylinder, digital balance, dropper.
Method:
Design a method that will allow you to have all of the data required to isolate viscosity from
the relationship above.
Data Processing and Presentation:
Process your data and plot a suitable graph from which you can determine the relationship
between the variables and estimate the viscosity of washing up liquid.
Conclusion and Evaluation:
Evaluate the data that you have collected and analyzed.
Evaluate the method, including any modifications you had to make to overcome problems.
Include an evaluation of the apparatus used.
Suggest ways in which the procedure could be modified in order to improve its result for
the future.
-1-
, Viscosity of Dish Soap
RESEARCH QUESTION:
How does the radius of the falling ball (independent variable) affect the
terminal velocity (dependent variable) in the estimation of the viscosity of dish
soap?
HYPOTHESIS:
By using the equation (2(pm-pl)rn) = V, it shows that with an increased radius of
a ball, the terminal velocity of the ball in a viscous liquid will rise proportional to r² where
pm is the density of the ball and pl is the density of the liquid. As well as η is the viscosity.
It would tend to imply that larger balls would fall faster through the liquid, assuming other
variables have been controlled.
VARIABLES:
Independent Variable(s): Dependent Variable(s):
● Radius of the ball (r) ● Terminal velocity (v) of the ball
as it falls through the liquid
Controlled Variable(s):
Temperature of the washing up liquid (affects viscosity)
Volume of washing up liquid in the cylinder
Density of the liquid (assumed constant for the experiment)
Initial height of ball drop
MATERIALS USED:
● Measuring cylinder (graduated)
● Digital balance
● Dropper (Tweezers)
● Small spherical balls of different radii (uniform density)
● Stopwatch or motion sensor for time measurement
● Ruler or caliper for measuring radius
-2-
Grade: 11 IB-DP Name: Tamara
Lab: To estimate the viscosity of washing up liquid
Aim:
To estimate the viscosity of washing up liquid using the velocity of a ball falling through the
liquid.
Formula :
Fd = 6𝛑ηrv
Apparatus:
Measuring cylinder, digital balance, dropper.
Method:
Design a method that will allow you to have all of the data required to isolate viscosity from
the relationship above.
Data Processing and Presentation:
Process your data and plot a suitable graph from which you can determine the relationship
between the variables and estimate the viscosity of washing up liquid.
Conclusion and Evaluation:
Evaluate the data that you have collected and analyzed.
Evaluate the method, including any modifications you had to make to overcome problems.
Include an evaluation of the apparatus used.
Suggest ways in which the procedure could be modified in order to improve its result for
the future.
-1-
, Viscosity of Dish Soap
RESEARCH QUESTION:
How does the radius of the falling ball (independent variable) affect the
terminal velocity (dependent variable) in the estimation of the viscosity of dish
soap?
HYPOTHESIS:
By using the equation (2(pm-pl)rn) = V, it shows that with an increased radius of
a ball, the terminal velocity of the ball in a viscous liquid will rise proportional to r² where
pm is the density of the ball and pl is the density of the liquid. As well as η is the viscosity.
It would tend to imply that larger balls would fall faster through the liquid, assuming other
variables have been controlled.
VARIABLES:
Independent Variable(s): Dependent Variable(s):
● Radius of the ball (r) ● Terminal velocity (v) of the ball
as it falls through the liquid
Controlled Variable(s):
Temperature of the washing up liquid (affects viscosity)
Volume of washing up liquid in the cylinder
Density of the liquid (assumed constant for the experiment)
Initial height of ball drop
MATERIALS USED:
● Measuring cylinder (graduated)
● Digital balance
● Dropper (Tweezers)
● Small spherical balls of different radii (uniform density)
● Stopwatch or motion sensor for time measurement
● Ruler or caliper for measuring radius
-2-
