Measurement is the starting point of meaningful scientific understanding. Micrometers are common pieces of equipment used across science and engineering that allow object dimensions to be measured with a high degree of accuracy and precision. This can be vital for designing mechanical components or for experiments in which sample dimensions affect the outcomes, e.g. resistance or stress.

Use this experiment to find out more!

Download the file below for the quick guide for the Micrometer experiment or follow these brief instructions:

1. Click on the rotating thumbscrew and drag up or down to open or close the micrometer, the further you move with your mouse the faster it will rotate.
2. Open the micrometer and drag a sample into the gap between the spindle and anvil. The sample will snap into place.
3. Close the micrometer around the sample with the rotating thumbscrew.
4. Read width from the micrometer scale (see below for how to do this).
5. Type width into the appropriate text box and click ‘Check’ to see if you were right (green = correct, red = incorrect).
6. Drag a sample out of the jaws (or press ‘Reset’) to return it to its original 
place and select a new sample.

You can also click ‘New’ for a fresh set of samples with different widths.

To read the micrometer scale (see full instructions for more details):

• Find the largest valued tick mark on the main scale that is revealed from behind the rotating thumbscrew. This gives a whole number of millimetres for sample width. 
• Locate the tick mark on the rotating scale that is most closely aligned with the main scale axis. This gives the number of tenths of a millimetre in the sample width.
• Add the values from the above steps to find the overall sample width.

Download the file below for full instructions for the Micrometer experiment.

1. Measure the diameter of ten ball bearing samples. Check to see how many you measure correctly and give yourself a mark out of ten. Repeat this until you get 10/10 every time! 
2. Error analysis:
   1. Measure and record the diameter of ten or more ball bearing samples. 
   2. Use the width data to calculate the volume of each sphere. 
   3. Determine the absolute uncertainty and percentage uncertainty for each diameter measurement. 
   4. Determine the absolute uncertainty and percentage uncertainty for each volume value. 
3. Statistical analysis:
   1. Measure and record the diameter of ten or more ball bearing samples. 
   2. Calculate the mean and standard deviation of the diameter measurements. 
   3. (Advanced experiment) Calculate the standard error of the diameter measurements and from this determine the confidence level of the mean.

Measurement is the starting point of meaningful scientific understanding. Callipers are common pieces of equipment used across science and engineering that allow object dimensions to be measured with a high degree of accuracy and precision. This can be vital for designing mechanical components or for experiments in which sample dimensions affect the outcomes, e.g. resistance or stress.

Use this experiment to find out more!

Download the file below for the quick guide for the Callipers experiment or follow these brief instructions:

1. Drag the moveable part of the lower jaw to make jaw separation larger than the sample width.
2. Drag the sample into the lower jaws. Sample will snap into place.
3. Drag the moveable jaw blade to close the jaws around the sample.
4. Read the width from the scale (see below for how to do this).
5. Open the jaws and drag the sample out to return it to its original place and select a new sample.

To read the calliper scale (see full instructions for more details):

• Find the tick mark on the main scale (upper scale) that is just below the ‘zero’ mark on the Vernier scale (lower scale). This gives a whole number of millimetres for sample width.
• Locate the tick mark on the Vernier scale that is most closely aligned with any tick mark on the main scale. This gives the number of tenths of a millimetre in the sample width.
• Add the values from the above steps to find the overall sample width.

Download the file below for full instructions for the Callipers experiment.

1. Measure the width of ten samples. Check to see how many you measure correctly and give yourself a mark out of ten. Repeat this until you get 10/10 every time! 
2. Error analysis:
   1. Measure and record the width of ten or more samples. 
   2. Use the width data to calculate the cross-sectional area of each sample. 
   3. Determine the absolute uncertainty and percentage uncertainty for each width measurement. 
   4. Determine the absolute uncertainty and percentage uncertainty for each cross-sectional area value. 

3. Statistical analysis:

   1. Measure and record the width of ten or more samples. 
   2. Calculate the mean and standard deviation of the width measurements. 
   3. (Advanced experiment) Calculate the standard error of the width measurements and from this determine the confidence level of the mean.

What is ‘Tensile Testing’?

The ‘tensile’ properties of a material describe its most basic mechanical behaviour – how much does a material stretch when it is pulled and how much of the stretching is permanent? ‘Tensile Testing’ is the process of measuring a material’s tensile properties. 

Why are tensile properties important?

Understanding of tensile properties is vital for any application that uses materials structurally, i.e. to withstand or apply force. The range of uses this covers is enormous. Strong and stiff structures are used in vehicles (cycles, cars, trains, aeroplanes, spacecraft), bridges and buildings, sports equipment and bio-implants (e.g. hip joint replacements). Flexible materials are also used in many of these applications. Thin but robust materials are used in touchscreens. Hard materials are used in machines and robots that process and shape other materials and as durable coatings that improve the performance and lifetime of aerospace and bio-implant components. Elastic materials can be stretched enormously before any permanent change is made and are used in springs and high performance fabrics. And it’s not just how a component is used – many manufacturing processes involve changing a component’s shape or response to applied forces, e.g. extrusion to make tubes, beams and bottles; drawing to make springs or wires; or forging and rolling to shape and harden metals.

Use this experiment to find out more!

​Download the file below for the quick guide for the Tensile Testing experiment (requires login) or follow these brief instructions:

To select a sample:

• Click the lower jaw to go to the sample view.
• Open the calliper jaws, drag a sample of choice between the jaw and fully close the jaws around it. (In this LITE version you can only select one of the samples).
• Use the Vernier scale to measure the sample width.
• Click the sample held in the callipers to use it in the tensile testing machine.
• Or open the callipers, return the sample to its original position and choose another sample. (Only available in the full version).

To set the strain increment:

• Click the Set button (display starts to flash).
• Use the keypad and the Del button to enter the desired Step value.
• Click the Set button again (display stops flashing).

To apply strain to samples:

• Set the strain increment value as described above.
• Click the up arrow to increase the applied strain by the Step increment value.
• Click the down arrow to decrease the applied strain by the Step increment value.
• Measure (and record) the applied load (force) using the needles on the Load dial.
• Turn off the strain control unit and click on the lower sample holder to select a new sample.

Download the file below for full instructions for the Tensile Testing experiment (requires login).

Structural materials are required to withstand a variety of applied loads in use. Understanding how these materials respond to the applied loads is vital for informed materials selection. Here we investigate how materials behave under tensile loading (loads applied along the length of a material to cause stretching).

The Tensile Test experiment allows a number of mechanical tests to be performed on materials, including:

• Determination of full stress-strain curve to fracture, using either ‘engineering’ or ‘true’ value
• Observation of elastic behaviour and calculation of Young’s modulus
• Observation of the onset of plastic behaviour and permanent deformation
• Calculation of moduli of resilience and toughness
• Calculation of strain energy in a system
• Calculation of work done in deforming a sample

Download the file below for activities for the Tensile Testing experiment (requires login). 

• QUICK ACTIVITIES: 9 quick activities to try
• ACTIVITY 1: Elastic deformation
• ACTIVITY 2: Plastic deformation
• ACTIVITY 3: Fracture

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

We have also provided a spreadsheet file to allow you to enter your SAMPLE WIDTH, STRAIN and APPLIED LOAD data and obtain stress-strain plots. (HINT: to investigate the general form of stress-strain curves with younger students, use a default sample width of, say, 7 mm)

Watch the video above and download the file below for the background science behind the Tensile Testing experiment (requires log in).

Thermodynamics and engine cycles are relevant to most areas of technology and science.

The behaviour of gases is used directly in applications as diverse as compressors, refrigerators, power generation from steam-driven turbines (used in gas-fired, coal-fired or nuclear power stations), pumping of gases (from natural gas pipe networks to aqualungs), and transport vehicles using petrol and diesel engines (combustion engines), jet and rocket engines, high performance tyres (e.g. for F1 cars) and even hot air balloons!

Thermodynamics is relevant far more widely though and to any system in which there is a change in energy, volume or ordering. This is relevant to almost every process around us, from sub-atomic particles forming atoms to the expansion of the universe and taking in atoms bonding to make a molecule or crystal (Physics), molecules reacting with each other (Chemistry), all biological processes (Biology), the weathering of rocks and tectonic plate movement (Geology). Even your breathing while you read this and your eye converting light into electrical signals so you can read this are thermodynamic processes. All energy technologies, materials manufacturing or recycling, chemical processing, transport technologies and even information technologies rely upon the principles of thermodynamics.

Thermodynamics and gas laws are, therefore, incredibly important topics. The FlashyScience Gas Laws virtual experiment allows you to start to explore this fascinating area of science and engineering.

Use this experiment to find out more!

Download the file below for the quick guide for the Gas Laws experiment (requires login).

Download the ‘How To’ attachments for step-by-step instructions on conducting experiments for:

• Constant pressure
• Constant temperature
• Constant volume

Download the file below for full instructions for the Gas Laws experiment (requires log in).

​Download the files below for activities for the Gas Laws experiment (requires login).

• QUICK ACTIVITIES: 4 quick activities to try
• ACTIVITY 1: Temperature calibration
• ACTIVITY 2: Isothermal compression
• ACTIVITY 3: Constant pressure (isobaric) – Charles’ Law
• ACTIVITY 4: Constant volume (isovolumetric) – Gay-Lussac Law
• ACTIVITY 5: Adiabatic compression
• ACTIVITY 6: Thermodynamic cycles (Advanced users)

(Available as separate downloads and all activities)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Gas Laws experiment (requires log in).

What is ‘Tensile Testing’?

The ‘tensile’ properties of a material describe its most basic mechanical behaviour – how much does a material stretch when it is pulled and how much of the stretching is permanent? ‘Tensile Testing’ is the process of measuring a material’s tensile properties.

Why are tensile properties important?

Understanding of tensile properties is vital for any application that uses materials structurally, i.e. to withstand or apply force. The range of uses this covers is enormous. Strong and stiff structures are used in vehicles (cycles, cars, trains, aeroplanes, spacecraft), bridges and buildings, sports equipment and bio-implants (e.g. hip joint replacements). Flexible materials are also used in many of these applications. Thin but robust materials are used in touchscreens. Hard materials are used in machines and robots that process and shape other materials and as durable coatings that improve the performance and lifetime of aerospace and bio-implant components. Elastic materials can be stretched enormously before any permanent change is made and are used in springs and high performance fabrics. And it’s not just how a component is used – many manufacturing processes involve changing a component’s shape or response to applied forces, e.g. extrusion to make tubes, beams and bottles; drawing to make springs or wires; or forging and rolling to shape and harden metals.

Use this experiment to find out more!

​Download the file below for the quick guide for the Tensile Testing experiment (requires login) or follow these brief instructions:

To select a sample:

• Click the lower jaw to go to the sample view.
• Open the calliper jaws, drag a sample of choice between the jaw and fully close the jaws around it.
• Use the Vernier scale to measure the sample width.
• Click the sample held in the callipers to use it in the tensile testing machine.
• Or open the callipers, return the sample to its original position and choose another sample.

To set the strain increment:

• Click the Set button (display starts to flash).
• Use the keypad and the Del button to enter the desired Step value.
• Click the Set button again (display stops flashing).

To apply strain to samples:

• Set the strain increment value as described above.
• Click the up arrow to increase the applied strain by the Step increment value.
• Click the down arrow to decrease the applied strain by the Step increment value.
• Measure (and record) the applied load (force) using the needles on the Load dial.
• Turn off the strain control unit and click on the lower sample holder to select a new sample.

Download the file below for full instructions for the Tensile Testing experiment (requires login).

Structural materials are required to withstand a variety of applied loads in use. Understanding how these materials respond to the applied loads is vital for informed materials selection. Here we investigate how materials behave under tensile loading (loads applied along the length of a material to cause stretching).

The Tensile Test experiment allows a number of mechanical tests to be performed on materials, including:

• Determination of full stress-strain curve to fracture, using either ‘engineering’ or ‘true’ value
• Observation of elastic behaviour and calculation of Young’s modulus
• Observation of the onset of plastic behaviour and permanent deformation
• Calculation of moduli of resilience and toughness
• Calculation of strain energy in a system
• Calculation of work done in deforming a sample

Download the files below for activities for the Tensile Testing experiment (requires login).

• QUICK ACTIVITIES: 9 quick activities to try
• ACTIVITY 1: Elastic deformation
• ACTIVITY 2: Plastic deformation
• ACTIVITY 3: Fracture

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

We have also provided a spreadsheet file to allow you to enter your SAMPLE WIDTH, STRAIN and APPLIED LOAD data and obtain stress-strain plots. (HINT: to investigate the general form of stress-strain curves with younger students, use a default sample width of, say, 7 mm)

Watch the video above and download the file below for the background science behind the Tensile Testing experiment (requires log in).

Radioactive elements (radionuclides or radioactive isotopes) produce high energy particles and are used in a huge range of applications. Most people know about nuclear power, which converts the energy of radiation from uranium-238 or plutonium-239 into heat and then electrical power, even in small-scale form for remote applications (e.g. spacecraft). There are far more widespread uses all around us though.

Radionuclides are used in many medicinal applications. They can be used as tracers to follow fluid flow inside the body by detecting the radionuclide emitted radiation (e.g. technetium-99, thallium-201, iodine-131 and sodium-24). Medical imaging can use radioactive elements that naturally collect in particular parts of the body and image the radioactive emission. For example, iodine-131 is used to image the thyroid and other isotopes can be used for other organs, such as bones, heart, liver and lungs. Larger doses of the radionuclides (e.g. cobalt-60) are used to create a targeted radiotherapy treatment of cancer in these organs. It is even possible to detect the presence of Heliobacter pylori (an unwanted bacterium that can be in stomachs) with a simple breath test that uses carbon-14.

You may have radioactive materials in your home, school or workplace. Smoke detectors use alpha radiation from americium-241 to ionise smoke particles for detection. Glow-in-the-dark inks on clocks, watches and emergency signs that convert radioactive particle energy from promethium-147 into light.

You may also have food that has been treated with radiation. Many foods (including tomatoes, mushrooms, berries, cereals, eggs, fish and some meat products) are irradiated with gamma rays from cobalt-60 to kill micro-organisms and improve the food’s shelf life (without making the food radioactive!). Similarly, gamma radiation from caesium-137 is used to sterilise medical products such as syringes, heart valves, surgical instruments and contact lens solutions.

Radioactive elements are used in industry too. For example, the absorption of different types of radiation mean it can be used to monitor the thickness of manufactured components and sheets. Radionuclides are also used for detecting leaks from pipes, the direction of underground pipes and waste dispersal in the environment. Radioactive sources are also used in industrial imaging, with the sample placed between the radiation source and a detector. Certain isotopes are used as chemicals in order to trace chemical reaction routes, e.g. carbon-14 in photosynthesis. Similar approaches are used in biology to test when proteins undergo important ‘phosphorylation’ reactions (using phosphorus-32) to learn when their function is activated by other proteins or small chemicals.

Radioactive elements can also be used for historical dating of objects, e.g. carbon-14 dating for estimating the age of organic matter and uranium-238 for rocks. Similarly, radioactive decay from vintage drinks such as wine can be used to prove their age, since radionuclides were released into the atmosphere by nuclear explosion tests after World War II and are present in all food and drink produced since then.

With so many uses, it’s no wonder that radioactive decay is an important aspect of science and engineering!

Use this experiment to find out more!

​Download the file below for the quick guide for the Radioactivity experiment (requires login) or follow these brief instructions:

Select the radiation source:

• Click on the Source holder.
• Click on one of the radiation sources in the tray and then in the holder.

Detecting radiation:

• Click the power switch on the Geiger-Müller counter.
• Read the needle position on the dial to measure level of radiation.

Changing the filter material and thickness:

• Click on the filter holder.
• Click on the material of choice to increase its thickness in the holder by 1 mm.
• Click on the material in the holder to reduce its thickness by 1 mm.
• Measure the filter thickness using the markings inside the holder.

Change the source-detector separation:

• Click and drag the holder mount to move it along the ruler.
• Measure the mount’s position using the magnified ruler view seen while clicked on the holder mount.

Time travel!

• Move time forward by one minute, hour, day, month or year by clicking on the appropriate value on the clock.

Download the file below for full instructions for the Radioactivity experiment (requires log in).

Download the file below for activities for the Radioactivity experiment (requires login).

• ACTIVITY 1: Radioactive half-life… and time travel! (used in GCSE Physics)
• ACTIVITY 2: Inverse square law (used in A-level Physics)
• ACTIVITY 3: Which materials absorb different types of radiation?
• ACTIVITY 4: Radiation absorption strength
• ACTIVITY 5: Alpha radiation (advanced experiment)
• ACTIVITY 6: Mixed radiation sources

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

Or see if you can do some of the following:

• Measure the half-life of different sources (GCSE)
• Measure how detected gamma radiation varies with source-detector separation
• Find out how alpha, beta and gamma radiation is absorbed by various materials
• Explore multi-decay type radioactive sources

Download the file below for the background science behind the Radioactivity experiment (requires log in).

Most electrical or electronic circuits use the voltage across the circuit components to perform some task. This includes motors, sensors, speakers, computer chips, LEDs and diode lasers, communications antennas (e.g. in mobile phones), heaters, turbines, and mains electricity delivery to houses and industry.

It is important to know how to control the voltages in these circuits to make the applications work! The simplest circuit to start to understand this is the potential divider, which is made up of two resistors in series. Other circuits may be made of more advanced components but often use the same principles of voltage (i.e. ‘potential’) division. For example: two transistors in opposite high or low resistance states and connected in series are used to define whether a ‘logic gate’ is set to a digital (Boolean) value of 1 or 0, and are a fundamental building block of how a digital computer processor works.

Sensors can be made from a fixed resistor and a component that has a resistance that depends on whatever is being sensed connected, e.g. a thermistor for sensing heat or a light-dependent resistor for sensing light. A voltage applied to the two components in series allows the voltage across the fixed resistor to be a measure of the resistance of the sensing element’s resistance. This approach can avoid some difficulties of just using the single element, such as high power consumption.

Electrical heaters (including room heaters, cookers and hair dryers) use a fixed resistance heating element (e.g. a coil of wire) and a variable resistance transistor in series. The resistance of the transistor then controls how much voltage is across the heating element and, therefore, how much electrical heating is produced!

This experiment allows you to gain a good understanding of the potential divider. It also allows you to reinforce your understanding of Ohm’s law, how resistor coloured bands code for resistance, and how to use digital multimeters (DMMs), which you may have already met in the FlashyScience Ohm’s Law experiment.

Use this experiment to find out more!

​Download the file below for the quick guide for the Potential Divider experiment (requires login) or follow these brief instructions:

To measure resistance:

• On the right-hand Digital Multimeter (DMM) rotate the switch to resistance measurement.
• Click and drag the clips on the wires attached to the right-hand DMM so that they snap to the wires either side of either or both resistors (make sure the power supply is turned off).
• Note the resistance value shown on the DMM screen.

To change a resistor:

• Click the resistor you wish to change to move to the Selection screen.
• Click on the colour band you wish to change.
• Click on the palette colour you wish to select.
• Click on the resistor wire to return to the main screen.

To measure voltage and current:

• Turn on the power supply (right hand side of screen) and turn the dial to set the voltage.
• To measure current through the resistor – turn the left-hand DMM dial to DC current.
• To measure the voltage across the resistor – turn the right-hand DMM dial to DC voltage.
• NOTE: the output voltage of the power supply is also shown on its display.

Download the file below for full instructions for the Potential Divider experiment (requires log in).

Download the file below for activities for the Potential Divider experiment (requires login).

• ACTIVITY 1: Investigate how the resistances of resistors in series combine
• ACTIVITY 2: Investigate how the current in a potential divider is controlled
• ACTIVITY 3: Explore how voltage in a potential divider depends on the resistor values
• ACTIVITY 4: Consider the voltage ratios across resistors in a potential divider
• ACTIVITY 5: Achieve certain voltages by changing the resistor values
• ACTIVITY 6: Explore power consumption in a potential divider
• ACTIVITY 7: Achieving particular property values in potential dividers
• ACTIVITY 8: Design a potential divider heating element
• ACTIVITY 9: Design a volume control element
• ACTIVITY 10: Design a sensor circuit

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Potential Divider experiment (requires log in).

Electronic materials are crucial to our life today, and electrical ‘resistivity’ tells us how good or poor a material is at conducting electricity.

We use materials with low electrical resistivity to transmit electrical power from generators, across grid distribution networks, and to homes and workplaces for use. Designers of electrical devices rely on knowing the resistivity of wire used in order to calculate the resistance of components.

These devices range in size from enormous machines such as wind turbines or industrial lifting equipment; motors or engines in electric vehicles and all-new electric aircraft; consumer products such as washing machines, hair dryers and ovens; and the nanoscale components within the computer chips found in smart devices, laptops, and mobile phones.  

In fact, modern computing is based on controlling the resistivity of semiconductor materials in a type of transistor (known as ‘field effect transistors’ using ‘CMOS’ technology).

Measuring electrical resistivity helps us to understand the properties of materials, to monitor manufacturing processes, and to select the best material for an application.

Use this experiment to find out more!

Download the file below for the quick guide for the Resistivity of a Wire experiment (requires login) or follow these brief instructions:

1. Click on the right hand wire post to move to the Select Wire screen.
2. Open the micrometer by dragging the thumbwheel down.
3. Choose a material and drag the unlabelled wire into the micrometer.
4. Close the micrometer and measure the wire's width.
5. Click on the wire while it's in the micrometer to return to the main screen.
6. Click on the switch to turn it on.
7. Measure voltage and current for a variety of contact positions on the wire.
8. Calculate resistance for each contact position. 
9. Plot resistance vs contact position and calculate the gradient of a line of best fit.
10. Multiply the line's gradient by the wire's cross-sectional area to obtain the wire's electrical resistivity.

Download the file below for full instructions for the Resistivity of a Wire experiment (requires log in).

Download the file below for activities for the Resitivity of a Wire experiment (requires login).

• QUICK ACTIVITIES: 5 quick activities to try
• ACTIVITY 1: Different wire lengths

(Available as separate downloads or all activities)

*NEW* Now also available in editable Microsoft Word format

Download the file below for the background science behind the Resitivity of a Wire experiment (requires log in).