Help with educational research!

[EricaC]

Hi all, I am in the process of adding physics to my teachable subjects, and I have a project due soon where I have been asked to improve upon a Leaving Certificate Physics experiment. The only thing is I haven't actually taught physics yet, and was wondering if any teachers could share their thoughts on the experiments and any challenges you have faced or any improvements you would like to see made to the experiments.

 

[berkeman]

Welcome to PF.

improve upon a Leaving Certificate Physics experiment

What is that? Can you give more details about the experiments, and perhaps some links to what you are talking about?

Also, if you don't have a physics education yet, is it realistic for you to try to teach it?

 

[EricaC]

Hi all, I am in the process of adding physics to my teachable subjects, and I have a project due soon where I have been asked to improve upon a Leaving Certificate Physics experiment. The only thing is I haven't actually taught physics yet, and was wondering if any teachers could share their thoughts on the experiments and any challenges you have faced or any improvements you would like to see made to the experiments.

Welcome to PF.


What is that? Can you give more details about the experiments, and perhaps some links to what you are talking about?

Also, if you don't have a physics education yet, is it realistic for you to try to teach it?

I do have a physics education. I was asking if any people who are currently teaching physics have any comments on the mandatory experiments that students have to complete for the Irish leaving certificate as I have to do a project which aims to improve on the experiments.

 

[berkeman]

I do have a physics education.

Oh, sorry that I misunderstood what you wrote. Thanks for the clarification.

Can you post some links to the Irish Leaving Certificate experiments?

 

[EricaC]

Oh, sorry that I misunderstood what you wrote. Thanks for the clarification.

Can you post some links to the Irish Leaving Certificate experiments?

https://www.pdst.ie/sites/default/files/ph_pr_alllistedphysexpr.pdf

 

[kuruman]

Can you post some links to the Irish Leaving Certificate experiments?

There is a whole bunch of them here
https://www.pdst.ie/sites/default/files/ph_pr_alllistedphysexpr.pdf

To @EricaC:
How familiar are you with these experiments? From my experience with designing and teaching experiments at this level, improvements don't come to mind unless one actually performs them.

I can see that there is room for improvement in one of them (only because I taught it) and that is measuring the acceleration of gravity with a pendulum. Here is the procedure

There is considerable room for introducing uncertainties in step 5. Exactly how does one about measuring the length of a pendulum (independent variable) from the point of support to the center of the bob which has a sizable diameter?

Is this the sort of improvement you are looking for or are you looking for complete redesign of the experiments or the selection thereof?

 

[EricaC]

There is a whole bunch of them here
https://www.pdst.ie/sites/default/files/ph_pr_alllistedphysexpr.pdf

To @EricaC:
How familiar are you with these experiments? From my experience with designing and teaching experiments at this level, improvements don't come to mind unless one actually performs them.

I can see that there is room for improvement in one of them (only because I taught it) and that is measuring the acceleration of gravity with a pendulum. Here is the procedure

View attachment 365546
There is considerable room for introducing uncertainties in step 5. Exactly how does one about measuring the length of a pendulum (independent variable) from the point of support to the center of the bob which has a sizable diameter?

Is this the sort of improvement you are looking for or are you looking for complete redesign of the experiments or the selection thereof?

Thanks for this response! It’s these types of improvements I’m looking for! Just some thoughts on how to introduce more concepts or even how to make the set up easier for teachers or students!

 

[kuruman]

I have a problem with the very first experiment. In my opinion, its educational value needs to be re-examined because it unintentionally conveys the wrong message to the student(s) who perform it. One is asked to measure the constant velocity of a trolley moving down an inclined ramp.

The intended educational value of this "experiment" is to establish in the student's mind the idea that equal spacings on the in equal distances.

OK, but what will you, as a teacher, say to a student who puts a piece of chalk on the incline and watches it roll downhill starting from rest? Here is my imagined dialogue.
Student: Is the chalk not accelerating?
You: Of course it is. It is initially at rest and then, at a later point, it is moving faster and faster.
Student: Then how come the trolley is moving at constant velocity on the same incline?
You: This is an idealisation. The trolley would normally accelerate when placed on the incline. However, friction on the tape that it being dragged, air resistance, friction at the wheels' axles etc. provide an opposing force to the downhill component of gravity. If the trolley were on a horizontal surface in this setup, it would decelerate and stop. We need the incline to compensate for the dissipative forces.

@kuruman's recommendations (free of charge)
Toss this experiment because it hides the truth and reinforces the incorrect idea that something rolling down an incline can do so at constant velocity. Since photogates are available for these experiments, use them instead with commercially available photogate picket fences. Rewrite the first two experiments.

 

[EricaC]

I have a problem with the very first experiment. In my opinion, its educational value needs to be re-examined because it unintentionally conveys the wrong message to the student(s) who perform it. One is asked to measure the constant velocity of a trolley moving down an inclined ramp.

View attachment 365548
The intended educational value of this "experiment" is to establish in the student's mind the idea that equal spacings on the in equal distances.

OK, but what will you, as a teacher, say to a student who puts a piece of chalk on the incline and watches it roll downhill starting from rest? Here is my imagined dialogue.
Student: Is the chalk not accelerating?
You: Of course it is. It is initially at rest and then, at a later point, it is moving faster and faster.
Student: Then how come the trolley is moving at constant velocity on the same incline?
You: This is an idealisation. The trolley would normally accelerate when placed on the incline. However, friction on the tape that it being dragged, air resistance, friction at the wheels' axles etc. provide an opposing force to the downhill component of gravity. If the trolley were on a horizontal surface in this setup, it would decelerate and stop. We need the incline to compensate for the dissipative forces.

@kuruman's recommendations (free of charge)
Toss this experiment because it hides the truth and reinforces the incorrect idea that something rolling down an incline can do so at constant velocity. Since photogates are available for these experiments, use them instead with commercially available photogate picket fences. Rewrite the first two experiments.

These are exactly the kind of thoughts I was looking for! Thank you for taking the time to respond

 

[kuruman]

To @EricaC:

It occurred to e that you might wish to explore the use of smartphones in physics experiments. Not all schools have photogates and thermistors but it's a safe bet that a great number of students have smartphones who will love the excuse for bringing them to school.

See here https://phyphox.org for example.