VCE Physics Question Thread!

[silverpixeli]

Hey guys, what is the best scientific calculator for physics? I have been using my green ti from year 7,but I find it sucks for gravity questions because you can't see the whole screen

I'm a big fan of the Canon F-717SGA. There's also a Casio going around with a few extra letters you can use to store constants like G and h and stuff.

[paper-back]

Thanks silverpixeli!

[alchemy]

Hey guys, what is the best scientific calculator for physics? I have been using my green ti from year 7,but I find it sucks for gravity questions because you can't see the whole screen

#greenti4lyf.....
I find that it does most of the things I want it to for vce physics.
As for not being able to see the whole screen, that's why there's an up button

[Adequace]

It's kind of a 1/2 physics questions and not really serious, but would you guys consider death an effect of radiation or the result of the symptoms of radiation?

I've heard it'll be a bonus question for our mid-year exam and we need to persuade our teacher on what it is, but I haven't come to a conclusion lol.

[Adequace]

Legitimate question now, for Q7. I'm not sure if I got it current but would it be 0A since the diode is in reverse bias or still 0.060A?


Edit: Would like help with the second picture as well, it relates to the same circuit. I think I got them wrong.

[silverpixeli]

Legitimate question now, for Q7. I'm not sure if I got it current but would it be 0A since the diode is in reverse bias or still 0.060A?


Edit: Would like help with the second picture as well, it relates to the same circuit. I think I got them wrong.

The diode is not in reverse bias mode in the first picture. When they turn it around, then it is reverse biased and then there's no current and that's why the light goes out. This answers the last question.

When a diode's triangle is pointing the same way as conventional current, it's in forward bias mode. Conventional current always comes out of the longer side of a battery symbol, as this represents the positive terminal.

[Adequace]

The diode is not in reverse bias mode in the first picture. When they turn it around, then it is reverse biased and then there's no current and that's why the light goes out. This answers the last question.

When a diode's triangle is pointing the same way as conventional current, it's in forward bias mode. Conventional current always comes out of the longer side of a battery symbol, as this represents the positive terminal.

In the image the cells are placed in different directions, so it looks to be that both ends have a longer side? I'm not sure if the question is supposed to be some sort of trick question.

[Floatzel98]

In the image the cells are placed in different directions, so it looks to be that both ends have a longer side? I'm not sure if the question is supposed to be some sort of trick question.

yeah, that cell on the left side, being the other way is a bit confusing. Is there a reason why it is like that? Because looking at the diagram alone, i might have actually said that that the direction of current was going from through ammeter 1 first (left to right) which places the diode in reverse bias. Plus you might think ammeter one and 2 would go in order, like they would place ammeter 1 where the current first comes out, and ammeter 2 after that at the end.

Also Adequace, what do you mean with your previous questions about radiation?

[Adequace]

yeah, that cell on the left side, being the other way is a bit confusing. Is there a reason why it is like that? Because looking at the diagram alone, i might have actually said that that the direction of current was going from through ammeter 1 first (left to right) which places the diode in reverse bias. Plus you might think ammeter one and 2 would go in order, like they would place ammeter 1 where the current first comes out, and ammeter 2 after that at the end.

Also Adequace, what do you mean with your previous questions about radiation?

It's just about the effects of exposure to radiation, nothing too important though!

[silverpixeli]

oooh i didn't see the reversed battery, sorry. anyway it just has the effect of cancelling one of the batteries going the other way. You can think that section as like -1.5V +1.5V +1.5V +1.5V and there's a net voltage supplied of 3V (equivalent to 2 batteries). That's probably a key step in solving the other problems.

This is an interesting electricity question relying on some nuances of Kirchoff's voltage laws that aren't really studied in year 12, so while it may be in your current course Adequace, it's certainly not something that other people should be worried about.

Long story short, one of the batteries being reversed just takes away from the total voltage that is being supplied and it's as if were were only 2 batteries there.

[silverpixeli]

It's just about the effects of exposure to radiation, nothing too important though!

From this page at gizmodo

How you would die

Large doses of ionizing radiation in a short time period lead to Acute Radiation Syndrome (ARS), aka radiation poisoning. The severity of ARS symptoms depends on the level of exposure. A radiation dose as low as 0.35 Gy could feel a bit like you have the flu—expect nausea and vomiting, headaches, fatigue, and fever. If the body is exposed to a higher dose, somewhere between 1-4 Gy, blood cells begin to die. You could still recover—treatment of this kind of radiation syndrome usually involves blood transfusions and antibiotics—but you could also suffer a weakened immune response due to a drop in white cell count, uncontrollable bleeding due to a lack of platelets, and anemia due to a reduction of red blood cells. You'll also notice a kind of odd sunburn if exposed to 2 Gy or more of ionizing radiation. Technically referred to as acute radiodermatitis, its effects include red patches, peeling skin, and sometimes blistering. Expect it to show up within 24 hours........ more

It goes on to detail the actual death... Scary stuff.

Based on this, I would say that the radiation's symptoms are death because it basically tears up the stuff that makes up your body and that causes everything to stop functioning properly and you die.

[Adequace]

Thanks for both replies silverpixeli!

[silverpixeli]

ah just wanted clear up what i just said,

would you guys consider death an effect of radiation or the result of the symptoms of radiation?

I'm calling it a symptom of the radiation (aka an effect of the radiation) rather than an effect of its symptoms but like this is a weird distinction to make. It's definitely not like high/sudden bursts of radiation give you some other disease which then kills you, they literally tear your atoms apart. That being said, long exposure to radiation causes increased genetic mutations in new cells and that leads to cancer which then takes over and kills you too, so in that case I guess death is the result of a symptom.

But yeah this is a weird question to answer because it's a fine line in my understanding between what actually kills you.

[Adequace]

Sorry for asking another question.

I've started unit 2 motion by myself and found myself confused with an answer/s. I've seen some answers of questions when the units have ^-2 instead of a ^-1, what does the ^-2 mean? I assume ^-1 means per 'sec/min/etc' but not sure on ^-2

[Cosec]

Sorry for asking another question.

I've started unit 2 motion by myself and found myself confused with an answer/s. I've seen some answers of questions when the units have ^-2 instead of a ^-1, what does the ^-2 mean? I assume ^-1 means per 'sec/min/etc' but not sure on ^-2

Exactly right. ^-1 means something/something. Stuff like meters/second (meters per second) can be written as ms^-1.
^-2 is similar. Most commonly used would be acceleration. In whihc case is something/something^2. Acceleration is meters/second/second (meters per second per second). And can be written as ms^-2. Or m/s^2