Launch: Worksheet 1a
Investigate how force, area and
pressure are related
1 Measure the area of one of the surfaces of a wooden block.
2 Place the wooden block carefully on a level sandy surface and place a 2kg mass on top of
the block.
3 Measure the depth of the impression left in the sand.
4 Test 4 more surfaces of different sizes.
5 Calculate the pressure generated by the combinations of area and force.
Use the equation:
P= F
A
Surface area
cm2
Depth of indentation
mm
Force Applied N
(2kg = 20N)
Pressure
N/cm2
6 Plot a graph of pressure against depth of indentation. Make sure the independent and
dependent variables are plotted on the correct axes and labelled accurately.
7 Describe and explain your results.
Launch: Worksheet 1b
2a
Investigate
how hydraulic systems
Further
Questions
work
force
multipliers
1 A man as
weighing
800N walks
on the
sand in his flip-flops (total area
300cm2). and
What
pressurethe
does
heof one of the syringe plungers (area of a circle is πr2).
1 Measure
calculate
area
generate?
2 Attach a second syringe with some tubing and then fill the system completely with water.
2 If his wife, weighing 400N, wears her
3 high
Carefully
input
force what
with a Newton meter to one syringe.
heelsapply
(totalan
area
50cm2)
pressure does she generate?
4 Calculate the pressure generated by syringe 1.
3 If the SupaCat launcher generates
5 Use
the equation
a pressure
of 62,053N/m2
P = Fand has a
A what
weight of 320,000N (32,000kg),
area presses on the sand?
6 Rearrange the formula and calculate the force that will be generated on syringe 2.
You can check this with a second Newton meter.
7 Test 4 more different combinations of syringes
Syringe 1
Area/cm2
Output Force/N
Syringe 2
Pressure/N
Area/cm2
Output Force/N
Launch: Worksheet 2
Investigate how hydraulic systems
work as force multipliers
1 Measure and calculate the area of one of the syringe plungers (area of a circle is πr2).
2 Attach a second syringe with some tubing and then fill the system completely with water.
3 Carefully apply an input force with a Newton meter to one syringe.
4 Calculate the pressure generated by syringe 1.
5 Use the equation
P= F
A
6 Rearrange the formula and calculate the force that will be generated on syringe 2.
You can check this with a second Newton meter.
7 Test 4 more different combinations of syringes
Syringe 1
Area (m2)
Output Force (N)
Syringe 2
Pressure (N/m2)
Area (m2)
Output Force (N)
Launch: Worksheet 3
Investigate how the output force of a jet propulsion system
could be affected by the area of the water jet nozzle
1 You will be given a balloon and a small length of tapered tubing to model a jet propulsion
system. If the inflated balloon is attached to the thicker end of the tubing and allowed to
deflate the tubing will act as a force multiplier.
2 Design a simple ‘force meter’ to measure how big a force is being produced by your ‘jet
propulsion system’. One simple idea could be to hang a piece of card from a clamp using
sticky tape and direct the air flow towards it. The bigger the angle of the card when it is
pushed, the more force has been generated by the air flow.
3 Measure the size of the nozzle and the force generated. Repeat 3 times.
4 Cut the nozzle to increase the outflow size and repeat experiment.
5 Continue until the nozzle is not tapered anymore.
Size of nozzle
(cm or cm2)
Force generated (arbitrary units)
1
2
3
Mean
Analysis
Evaluation
1. Draw a line graph of your results
2. What was your independent variable?
How did you change it?
3. What was your dependent variable? How
did you measure it?
4. Describe and explain the trend shown by
your investigation.
1. What were your control variables?
How did you ensure they were kept the
same?
2. Were your results reliable? How can you
tell?
3. How could you have improved your
investigation?