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Physics Labs For Independent Learning

Daniel Muttiah

My first-year physics professor, Dr. D.S. Scott, in my first year of university said something that has stayed with me over the years. During one of his lectures he asked the question: where is the best physics lab located? There were various responses from different students and his response was a no to all the major labs mentioned. Finally he responded with the statement: the best physics lab is the world around you. I have not forgotten Professor Scott's words of wisdom which have inspired me over the years, both in my learning and in my teaching.

I am currently teaching physics in a hybrid learning environment (online and in-person with social distancing) due to the covid-19 pandemic. This new structure has caused significant limitations on group work and interaction between students. One of the losses in this new reality is the inability for students to conduct labs and hands on activities to explore the concepts of physics. One solution to this problem is using computer simulations, which has been a go to choice for many physics teachers. Another solution to this problem are demonstration labs, where the teacher does the lab while the students watch, either in person or remotely, and record and analyze data. Though both of these are viable options for student learning, in my opinion it is not as ideal as a lab that is conducted by students. The learning involved in the different aspects of an experiment; such as, setting up, collecting the data, analyzing the data to reach a conclusion and considering sources of error are all inter-related. Therefore, enabling students to perform real labs on their own would be the gold standard to aspire to as a physics teacher. This ideal was recognized by Aristotle when he said: what we have to learn to do we learn by doing. The American educational philosopher John Dewey also expounded this thinking in more recent times.

To have students performing labs while learning remotely or under restrictive social distancing rules we must expand our notion of what a lab is, from a room to where experiments are conducted, to the world around us that can be investigated. A shift in mindset that I was introduced to 30 years ago. Here are three different approaches to performing physics labs remotely that can help us to achieve the goal of students performing labs under the current pandemic restrictions.

Option 1: Video Analysis
Video recording capabilities are now commonly available on different types of devices: smartphones, laptops, tablets, and cameras. A video recording device can be used to perform physics labs at home, especially labs involving motion. Consider a simple lab of measuring the acceleration due to gravity that can be done at home. The motion of a small object tossed vertically upwards in front of a wall with vertical length markings can be recorded and analysed to determine the acceleration due to gravity. The frame by frame analysis can be done using VLC media player (free), YouTube, or any other software. Students can determine the position of the object at different moments in time by considering the frame rate of the video and the number of frames. This data can be used to create a displacement-time graph. From the data the mid-point approximation can be used to determine the velocity-time graph, which then yields the acceleration of the object. The acceleration obtained by the students can be compared to the accepted value of 9.8 m/s2.

Option 2: Indirect measurements
Indirect measurements are a fun way to explore the ideas of physics through hands on lab activities. Consider the case of measuring the temperature of cold tap water (ideally after running the water for a few minutes to avoid localized heating/cooling of the water). This can be accomplished by using an electric kettle, a timer, and a knowledge of energy concepts. In this case, students first determine the wattage of the electric kettle by locating the label on the electric kettle. Once this is determined, they bring 1L of tap water to boil in the kettle. By measuring the time it takes for the water to first comes to a boil and using the physical characteristics of water (density and specific heat capacity) the students would be able to determine the initial temperature of the water. The temperature obtained using this method can be compared to a direct measurement of the temperature using a thermometer. Given that a thermometer may not be available in every home, students can use a direct measurement value obtained by another student if they are resident in the same general area to establish the accuracy of their indirect measurement.

Option 3: Phyphox App
One of the challenges of at home lab activities is the cost of equipment, but thankfully this is made easier with technology that is becoming more and more prevalent. A smart phone with all its sensors is an incredible tool for collecting and analyzing data to understand physical phenomena. Physics app phyphox is an excellent tool for students to conduct labs at home. The app is made freely available by Aachen University, Germany for both Android and Apple. Along with the app, Aachen University provides a website (www.phyphox.org) with instructions for different physics experiments, many of which can be easily adjusted to be done independently by students at home.

Though individual circumstances may be different for different students and teachers, the above three options provide greater opportunities for learning during the challenges imposed by the pandemic. Through these three broad approaches I have been able to enhance the learning of physics for my students. Similarly, I hope that you would be able to use and explore this approach to enable students to perform physics experiments independently.

Editors note: we published a more detailed review of phyphox here.
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