HSC Physics Question Thread

[blasonduo]

i need help understanding the right hand grip rule, i find the right palm rule easy tho. Do we have to know how to use the right hand grip for M and G?

Hey!!

If you understand the palm rule, the grip rule will be a breeze! As we know, a current carrying conductor will produce a magnetic field, and the grip rule shows us the direction of the magnetic field. It also explains why 2 wires carrying current in the same direction will attract. (I shall attach an image to show this)

This rule is fantastic at finding the north and south poles of a solenoid very quickly, as wrapping around your fingers in the same direction as current flow allows you to find the north side of the solenoid.

My personal experience is that we were required to use the right-hand palm rule a lot more times than the right-hand grip rule, but it is still very important!

Hope this helps!

[Abi21]

Hi, I'm struggling with two physics questions, hoping for a little bit of help please!

1) 0.5 kg of ice at 0 degrees is mixed with 0.1kg of steam at 100 degrees. What will be the final temperature?

2) A student attempts to identify metal by measuring the specific heat capacity. 100g of the metal is heated to 75 degrees and then transferred to a 70g copper calorimeter containing 200g of water at 20 degrees. The temperature of the final mixture is 25 degrees? What metal is the student testing? ( given a bunch of metals with their approximate specific heat capacity)

Thanks in advance!

[blasonduo]

Hi, I'm struggling with two physics questions, hoping for a little bit of help please!

1) 0.5 kg of ice at 0 degrees is mixed with 0.1kg of steam at 100 degrees. What will be the final temperature?

2) A student attempts to identify metal by measuring the specific heat capacity. 100g of the metal is heated to 75 degrees and then transferred to a 70g copper calorimeter containing 200g of water at 20 degrees. The temperature of the final mixture is 25 degrees? What metal is the student testing? ( given a bunch of metals with their approximate specific heat capacity)

Thanks in advance!

Hey! This content isn't in the HSC physics syllabus!

Maybe you were thinking of another thread?

[Abi21]

sorry wrong thread   

[clovvy]

I am stuck with this projectile question:
A daredevil tries to jump a canyon of width 10m.  To do so, he drives his motorcycle up an incline sloped at an angle of 15 degrees. What minimum speed is necessary to clear the canyon?

[blasonduo]

Hey!! Here is my working...

Spoiler

WHEWWW!!! That was a biggie! That being said, this is wayyy too hard for HSC physics, never expect this type of difficulty in your exams

[jamonwindeyer]

I am stuck with this projectile question:
A daredevil tries to jump a canyon of width 10m.  To do so, he drives his motorcycle up an incline sloped at an angle of 15 degrees. What minimum speed is necessary to clear the canyon?

We can approach this a little more simply than above if we're tricky. We know that the peak of motion will be at the halfway point of the parabola, meaning, when the range is five metres. However, we also know that the vertical velocity is zero at this point, so:



This needs to be, as mentioned, at a horizontal distance of 5 metres. So use the horizontal range formula:



Absolutely agree though, this is way up there as a projectiles question. If it did appear in a HSC exam, it would be right near the end, and probably in parts

[blasonduo]

We can approach this a little more simply than above if we're tricky.

Ah! I was wondering if there was an easier method! It still uses the substitution to solve it too!

Thanks for the help

[clovvy]

We can approach this a little more simply than above if we're tricky. We know that the peak of motion will be at the halfway point of the parabola, meaning, when the range is five metres. However, we also know that the vertical velocity is zero at this point, so:



This needs to be, as mentioned, at a horizontal distance of 5 metres. So use the horizontal range formula:



Absolutely agree though, this is way up there as a projectiles question. If it did appear in a HSC exam, it would be right near the end, and probably in parts

Hey guys thanks a lot for the assist because I did end up with a sec^2 at some point so I want to know a simpler way to do it.. by the way, why did you put the distance as 5m Jamon?

[jamonwindeyer]

Hey guys thanks a lot for the assist because I did end up with a sec^2 at some point so I want to know a simpler way to do it.. by the way, why did you put the distance as 5m Jamon?

Glad to help! This is because I wanted to analyse the point at the peak of the motion, when vertical velocity is zero. This always happens halfway through the motion, so if we need to travel a 10 metre distance total, that means we are analysing the variables at 5 metres - The halfway point

[Mate2425]

Hi, could someone please help me with the topic of projectile motion. I am finding it hard to understand the setting out for questions and when and when not to use certain formulas. I was wondering if anyone knew of any great resources or questions and answers that could help with this section of the syllabus.

Thanks,
Kind Regards,
Mate2425

[blasonduo]

Hi, could someone please help me with the topic of projectile motion. I am finding it hard to understand the setting out for questions and when and when not to use certain formulas. I was wondering if anyone knew of any great resources or questions and answers that could help with this section of the syllabus.

Thanks,
Kind Regards,
Mate2425

Hey!!

If you struggle with trying to figure out how to complete a question, here are some tips:

1) On the right-hand side, write down every variable. (ie range = ..... , time = ....)
2) Label the variable you are trying to find with a ?
3) Find if any variables = 0 (this is very prevalent in questions that drop an object, or is needed to calculate it's maximum height reached.
4) Look at the formula sheet and see if any equations have only your ? variable, and if so substitute and rearrange.
5) If not, try to solve the other variables, the more variables you can find, the easier it will be to find your known.

In my opinion, the questions that trick most people are the ones where you need to assume a variable as 0, and people just forget, remember to keep looking over this!
http://nsb.wikidot.com/pl-9-2-2-1 is a very good site to help you with this! (used it myself)

http://www.itute.com/2010/12/25/free-download-physics-worksheet-projectile-motion/ This is also a good source of questions!

If you need further help with anything specific, Feel free to ask! Always happy to help

[Mate2425]

Thank you blasonduo, much appreciated, absolute legend and very helpful   

Hey!!

If you struggle with trying to figure out how to complete a question, here are some tips:

1) On the right-hand side, write down every variable. (ie range = ..... , time = ....)
2) Label the variable you are trying to find with a ?
3) Find if any variables = 0 (this is very prevalent in questions that drop an object, or is needed to calculate it's maximum height reached.
4) Look at the formula sheet and see if any equations have only your ? variable, and if so substitute and rearrange.
5) If not, try to solve the other variables, the more variables you can find, the easier it will be to find your known.

In my opinion, the questions that trick most people are the ones where you need to assume a variable as 0, and people just forget, remember to keep looking over this!
http://nsb.wikidot.com/pl-9-2-2-1 is a very good site to help you with this! (used it myself)

http://www.itute.com/2010/12/25/free-download-physics-worksheet-projectile-motion/ This is also a good source of questions!

If you need further help with anything specific, Feel free to ask! Always happy to help

[itssona]

Einstein’s 1905 theory of special relativity made several predictions that could not be verified for many years. 
(a) State ONE such prediction. 
(b) Describe an experiment to test this prediction. 
(c) Explain how technological advances since 1905 have made it possible to carry out this experiment.    (HSC 2005)

So I said for part a about time dilation, and then I talked about the atomic clock experiment for (b) but what do I say for part C? kinda stuck

thanks guys

[not a mystery mark]

Heyyy.
I have a pretty easy physics question, anyway, here it goes.

A car accelerates at 2.5m/s^2 East for 16s. After this time the car is moving at 10m/s West. Calculate it's initial velocity.

The answer I got was -30m/s.  I just can't picture in my head somebody travelling West then all of sudden East.
ALSO: is it -30m/s East or West (or something completely different)

Thank you <3