Activity 2.4 Energy in, energy out
Equipment needed:
Each GROUP will require:

standard set of laboratory single, double and triple-sheaved pulleys

retort stand with boss heads and clamps

string

slotted masses

set of spring balances

metre ruler
Experiment 1: Single sheaf pulley
Instructions: Set up a single pulley as
shown in the diagram for Pulley 1. Place
different masses on the load side of the
pulley and measure the force required to
lift it. At the same time, measure the
height the load is lifted and the distance
the effort string has to be pulled.
Results:
Mass of load
(kg)
Weight of
load (N)
Distance of
load (m)
Effort (N)
Distance of
effort (m)
Pulley 1
Conclusion: How did the force needed to pull down compare to the load you were lifting?
What did this pulley achieve?
Energy • Activity 2.4 Energy in, energy out
1
Activity 2.4 Energy in, energy out
Experiment 2: Single-sheaf pulley
Try the same with Pulley 2, a different
arrangement of a single-sheaf pulley.
What did this pulley achieve?
What did you notice about the distance of
the effort and load?
Multiply the effort force by distance and
the load force by distance to compare how
much work was put into the pulley and
how much work you got out of it.
Results:
Mass of load
(kg)
Weight of
load (N)
Distance of
load (m)
Effort (N)
Distance of
effort (m)
Pulley 2
Energy • Activity 2.4 Energy in, energy out
2
Activity 2.4 Energy in, energy out
Experiment 3: Multiple-sheaf pulley
Instructions: Set up a pulley system
using two single-shear pulleys, as shown
in the diagram. Repeat Experiment 1
using this new system.
Take the same measurements and fill in
the first row of the table. Work is the
mechanical energy transferred through the
pulley, from the effort to the load
To calculate work, use the formula:
work = force x distance
Work is measured in Joules (J), force is
measured in Newtons (N), and distance
should be measured in metres (m).
Now calculate the Mechanical advantage
(MA) of the pulley.
Mechanical advantage = load/effort
Results:
Mass of
load
(kg)
Weight
of load
(N)
Distance
of load (m)
Work in
(J)
Effort
(N)
Distance Work out
of effort
(J)
(m)
MA
Pulley 3
Energy • Activity 2.4 Energy in, energy out
3
Activity 2.4 Energy in, energy out
Experiments 4 and 5: Complex pulleys
A pulley system using multiple sheafs is often called a block and tackle. A block and tackle
might be used to lift a motor from a car or a boat. Large container ships are unloaded by
enormous gantry cranes, which still use pulley systems to lift heavily loaded containers.
Now design two more complex pulleys using double- and triple-sheaf pulleys.
Draw the systems you have designed here. Label them Pulley 4 and Pulley 5.
Results:
Mass
of load
(kg)
Weight
of load
(N)
Distance
of load
(m)
Work
In
(J)
Effort
(N)
Distance
of effort
(m)
Work
out
MA
(J)
Pulley 4
Pulley 5
Conclusion: What conclusion can you make about how pulleys multiply force?
In your standard pulleys, where both the effort and the load are pulling down, how could you
work out the MA from counting the number of strings?
Energy • Activity 2.4 Energy in, energy out
4
Activity 2.7 Putting it together (Quiz)
You may refer to your Notebook.
Question 1 (Energy forms)
Name six different forms of energy and provide an example of each:
Energy form
Example
Question 2 (Energy transfers)
Give an example of each of the following energy transfers:
Mechanical energy to heat energy:
______________________________________________________________________________
______________________________________________________________________________
Gravitational potential energy to kinetic energy:
______________________________________________________________________________
______________________________________________________________________________
Electrical energy to sound energy:
______________________________________________________________________________
______________________________________________________________________________
Chemical energy to kinetic energy:
______________________________________________________________________________
______________________________________________________________________________
Energy • Activity 2.7 Putting it together (Quiz)
1
Activity 2.7 Putting it together (Quiz)
Question 3 (Mechanical energy)
A student throws a ball into the air and then catches it as it comes down. Explain how this shows
that mechanical energy is conserved:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Question 4 (Mass and weight)
A young student in Alice Springs has a mass of 40 kg.
What is her weight (using the proper scientific unit):
______________________________________________________________________________
If she were in orbit on the space station what would be her:
Mass?
______________________________________________________________________________
Weight?
______________________________________________________________________________
Question 5 (Pulleys)
A student designs the simplest block and tackle (pulley) system to lift a heavy rock alone. The rock
has a mass of 120 kg and the student has a mass of 39 kg. The student finds that he can use his
own body weight on this pulley system to lift the rock.
What is the mechanical advantage of this pulley system?
______________________________________________________________________________
______________________________________________________________________________
If he wants to lift the rock one metre, how much rope must be hauled through the pulley?
______________________________________________________________________________
______________________________________________________________________________
Question 6 (Starting fires)
Write a paragraph describing the energy transfers involved in starting a fire using the drill method.
You should include the following terms:
Mechanical energy
Kinetic energy
Heat energy
Light energy
Chemical energy
Energy • Activity 2.7 Putting it together (Quiz)
2
Activity 3.1 What is heat?
Activity 2.4 Energy in, energy out
Watch the animation. It is in three sections so you can answer the following questions:
Animation 1: Can you think of a fair test of Rumford’s idea that heat was caloric fluid?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Energy • Activity 3.1 What is heat?
1
Activity 3.1 What is heat?
Activity 2.4 Energy in, energy out
Animation 2: What results would you expect to see? What results would you expect if the theory of
caloric fluid was correct?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Energy • Activity 3.1 What is heat?
2
Activity 3.1 What is heat?
Activity 2.4 Energy in, energy out
Animation 3: How did Rumford’s observations disprove the caloric theory?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Energy • Activity 3.1 What is heat?
3
Activity 3.1 What is heat?
Conclusions
Activity 2.4 Energy in, energy out
People had observed that the cannon barrels got very hot when they were being bored out.
Cannon barrels were known to become hot when bored out.
1. What was Rumford’s hypothesis?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
2. Rumford proposed a fair test. Describe it.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
3. Why was it a good test of his hypothesis?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
4. The results were surprising. What were the observations?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
5. Did these results support or disprove Rumford’s hypothesis?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Energy • Activity 3.1 What is heat?
4
Activity 3.6 Solar energy
In this task you will design a system to heat water with sunlight. Complete the task in a small
group, but write an individual report.
What to do:
1. Design a device to collect sunlight to heat 1.25 L of water.
Your basic equipment includes:






a cardboard box
a PET bottle to hold 1.25 L
aluminium foil
cling wrap.
cold tap water (1.25 L)
thermometer.
You may use other equipment as needed. You may need to test your design, measure results and
adjust as needed.
2. Write your report with the following headings:







Aim: One or two sentences stating clearly what the investigation was designed to
achieve.
Materials: List equipment used.
Risk assessment: Identify and assess any risks and list precautions taken. Your
teacher will discuss this with you before you start.
Method: Record all steps and procedures used. You should clearly describe your
heater design. A diagram would be useful. You should then describe how you evaluated
your design. What measurements did you take? Use full sentences (this is called
prose) in past tense, as you are describing what you did.
Results: Record your observations and measurements showing how well your design
worked. A table of results might be easiest. You could use a histogram to show the
heating effect.
Discussion: You should explain:
 the scientific reasons behind your design
 how you evaluated whether it worked
 what improvements you made or those that could be made.
Conclusion: Summarise in one or two sentences how you achieved the best effect.
Energy • Activity 3.6 Solar energy
1
Activity 3.6 Solar energy
Marking Scheme: Report on water heater design
Name: ………………………………………………………………………………..
Area of
assessment
Heater design
Written report
Problem solving
Outcomes
Marks

Did the group go through an appropriate design and appraisal
cycle?
0
1 2

Could the group describe why they were using particular
designs using appropriate scientific language?
0
1 2

Is the aim stated clearly?

Is the list of materials complete?
0
1 2

Is there a suitable risk assessment?
0
1 2

Does the method describe the design and appraisal methods
clearly?
0
1 2

Is the data presented clearly?
0
1 2

Does the conclusion concisely reflect the aim?
0
1 2

Overall, is the writing clear and concise?
0
1 2
3

Does the discussion in the report draw on scientific
understanding?
0
1 2
3

Was there a logical and clear progression through the appraisal
and development of the heater?
0
1 2

Are there suggestions for future design improvements?
0
1 2
0
Total Mark
Energy • Activity 3.6 Solar energy
1
/25
2