Physics Practical Assessments (1 Viewer)

[appleali]

Hey guys,

In a few weeks I have my first HSC Physics assessment task. We are going to be doing a practical and then answering questions about it all in 1 hour. My teachers have said that it is basically easy marks, but I wanted to get the opinion of some other people.
Do I need to do any study and if so what study?
Also I've been told it will not assess any of the content we have done in class, and only will be a skills-based assessment.

Thanks

 

[helloworld!]

Hey guys,

In a few weeks I have my first HSC Physics assessment task. We are going to be doing a practical and then answering questions about it all in 1 hour. My teachers have said that it is basically easy marks, but I wanted to get the opinion of some other people.
Do I need to do any study and if so what study?
Also I've been told it will not assess any of the content we have done in class, and only will be a skills-based assessment.

Thanks

Is it on mod 6 by any chance?

 

[appleali]

Nope we are doing Mod 5 in class atm but teachers have assured us that no content is being assessed only skills

If you have any past papers I'd appreciate it so I can get the gist

 

[dk786]

Yeah my school haven't decided yet, but they said it's either a topic test or a skills test. I think brushing up on reliability, validity, accuracy, percentage errors and uncertainty (and the rest of stuff that is used in scientific reports) is the main way to study for this.

Also, even though content is not tested, make sure you are confident in answering theory questions. This will give you more confidence in the exam, which is crucial in this form of assessment.

Lastly, study the different assumptions that are made in projectile and circular motion. For example, in projectile motion we assume:

1. Projectile does not revolve
2. No air resistance
3. Value for g is constant
4. Earth is flat (curvature of earth is not accounted for, since projectile are typically launched over insignificant ranges)

These assumptions are typically useful in questions that ask "explain why obtained data differs from theoretical value etc."

Good luck!

 

[appleali]

Yeah my school haven't decided yet, but they said it's either a topic test or a skills test. I think brushing up on reliability, validity, accuracy, percentage errors and uncertainty (and the rest of stuff that is used in scientific reports) is the main way to study for this.

Also, even though content is not tested, make sure you are confident in answering theory questions. This will give you more confidence in the exam, which is crucial in this form of assessment.

Lastly, study the different assumptions that are made in projectile and circular motion. For example, in projectile motion we assume:

1. Projectile does not revolve
2. No air resistance
3. Value for g is constant
4. Earth is flat (curvature of earth is not accounted for, since projectile are typically launched over insignificant ranges)

These assumptions are typically useful in questions that ask "explain why obtained data differs from theoretical value etc."

Good luck!

Yeah thought so. I like the calculations questions more though haha

Does anyone have notes on VRAP/uncertainty stuff?

Thanks for your help

 

[Bob99]

if its mod 5, then its gonna be pendulum experiment most likely.
As that is the easiest to setup for the exam, and you can graph and measure data easily.
Your end goal would be to measure the value of g using various masses on a pendulum.

 

[appleali]

if its mod 5, then its gonna be pendulum experiment most likely.
As that is the easiest to setup for the exam, and you can graph and measure data easily.
Your end goal would be to measure the value of g using various masses on a pendulum.

Was looking through THSC online and saw some papers on this but unlikely because we already did measuring g with a pendulum in class.
Would be nice if it was that again tho lol

 

[liamkk112]

definetly study. my teachers said the exam was easy and everyone flopped lol. never trust this subject

 

[appleali]

Here a week after my exam (I got rank 1 yay), here's the run-down (at least for my school):
It was a 1 hour task. Our teacher had set up individual stations for each person in the class to do their experiment.

There was no Mod 5 content being assessed. Although springs related, no knowledge of this was required and it was skills-only (but again all this info is for my school so I can't guarantee it will be the same for yours)

We were recommended approx. 15 mins to complete the experimentation part. We were not assessed on how we carried out the experiment specifically but this would influence results and our validity answers later on.
- Our experiment was measuring the period of oscillation of a spring that had different masses hung off it to find the spring constant. We were given the formula for calculation of period, but that was it. We had to think of how we were going to do the experiment, create our own table and figure out our own way to find the spring constant. It was basically like an in-class practical but we weren't give a method or anything.
We had done a similar experiment in class before with a pendulum (the formulae are identical but different variables) so I knew exactly what to do for my table. I had columns for :

• Hanging mass
• 10 periods (I'll explain later)
• 1 period
• Period^2

I knew to measure 10 periods rather than one because this increases precision as the uncertainty is spread across multiple periods. Doing this, then dividing by 10 takes the absolute error to a further decimal place (+-0.5 to 0.05).
Sidenote: In our school, absolute error of a person measuring with a stopwatch is always +-0.5s. This is because although the stopwatch has up to 0.01s, the human reaction time must be accounted for.

For the second part, it was written. We had to calculate our best value, uncertainties and answer questions regarding VRAP.

1. Tabulate our data. Just make sure your table is clean, the top of each column includes units and uncertainties. My feedback was:
   1. Draw a box around your table, i.e close it up
   2. Give a title for the table (I know stupid, but physics teachers like to scab marks)
2. Give mathematical reasoning for our method to find k. In my case, and most others in the class, I rearranged to get the gradient of a linear T^2 vs. mass line and that would give me 4pi^2/k. However it will vary. You should always attempt to use the LOBF to get a best value as it is the most reliable method. An average is okay but if you can, you should 1000% use LOBF and gradient. Unless it is a qualitativate analysis (trend) or non-linear.
3. Draw a graph of our data. This is probably the biggest hint in our experiment to find the gradient of the LOBF.
4. Find the best value of k using our method
5. Find the absolute uncertainty of k
6. Answer question on validity (talk about assumptions how they were minimised and how they could minimised more)
7. Answer question on precision (uncertainty).

So this is how our exam looked like! So if yours is coming up, don't stress too much but take care to revise VRAP and absolute error propagation calculation. If you are not very mathematically oriented I would suggest practicing giving mathematical reasoning to find the best value. Also if you are given the opportunity to do practicals in class then I would suggest getting feedback from your teacher as that was a very valuable asset for me.

Best of luck with your exams

 

[C_master]

Here a week after my exam (I got rank 1 yay), here's the run-down (at least for my school):
It was a 1 hour task. Our teacher had set up individual stations for each person in the class to do their experiment.

There was no Mod 5 content being assessed. Although springs related, no knowledge of this was required and it was skills-only (but again all this info is for my school so I can't guarantee it will be the same for yours)

We were recommended approx. 15 mins to complete the experimentation part. We were not assessed on how we carried out the experiment specifically but this would influence results and our validity answers later on.
- Our experiment was measuring the period of oscillation of a spring that had different masses hung off it to find the spring constant. We were given the formula for calculation of period, but that was it. We had to think of how we were going to do the experiment, create our own table and figure out our own way to find the spring constant. It was basically like an in-class practical but we weren't give a method or anything.
We had done a similar experiment in class before with a pendulum (the formulae are identical but different variables) so I knew exactly what to do for my table. I had columns for :

• Hanging mass
• 10 periods (I'll explain later)
• 1 period
• Period^2

I knew to measure 10 periods rather than one because this increases precision as the uncertainty is spread across multiple periods. Doing this, then dividing by 10 takes the absolute error to a further decimal place (+-0.5 to 0.05).
Sidenote: In our school, absolute error of a person measuring with a stopwatch is always +-0.5s. This is because although the stopwatch has up to 0.01s, the human reaction time must be accounted for.

For the second part, it was written. We had to calculate our best value, uncertainties and answer questions regarding VRAP.

1. Tabulate our data. Just make sure your table is clean, the top of each column includes units and uncertainties. My feedback was:
   1. Draw a box around your table, i.e close it up
   2. Give a title for the table (I know stupid, but physics teachers like to scab marks)
2. Give mathematical reasoning for our method to find k. In my case, and most others in the class, I rearranged to get the gradient of a linear T^2 vs. mass line and that would give me 4pi^2/k. However it will vary. You should always attempt to use the LOBF to get a best value as it is the most reliable method. An average is okay but if you can, you should 1000% use LOBF and gradient. Unless it is a qualitativate analysis (trend) or non-linear.
3. Draw a graph of our data. This is probably the biggest hint in our experiment to find the gradient of the LOBF.
4. Find the best value of k using our method
5. Find the absolute uncertainty of k
6. Answer question on validity (talk about assumptions how they were minimised and how they could minimised more)
7. Answer question on precision (uncertainty).

So this is how our exam looked like! So if yours is coming up, don't stress too much but take care to revise VRAP and absolute error propagation calculation. If you are not very mathematically oriented I would suggest practicing giving mathematical reasoning to find the best value. Also if you are given the opportunity to do practicals in class then I would suggest getting feedback from your teacher as that was a very valuable asset for me.

Best of luck with your exams

thanks for this I have mine on Mon