General Thoughts: Physics (7 Viewers)

[AnimeX]

i got 1.19AU???

ffs im pretty sure I forgot to square the periods...

 

[Randox]

What was the reason for the person feeling gravity in the circle thingy lol

 

[Randox]

Also why did the mass of the planet not affect it's orbital speed around the star

 

[AnimeX]

It's 51.91 to two dp. Use centripetal acceleration and set it to 1g (9.8). Radius is 550/2

yay i got this too!

 

[Inverse]

What did you guys talk about for the braking one? I blanked out so I just bsed about eddy currents and EM braking lol yolo

 

[AnimeX]

Also why did the mass of the planet not affect it's orbital speed around the star

because the planet (normally this is the satellite) was rotating around the star (central body), and orbital speed = root( Mass central body / radius between the too objects) so it's independent

 

[Mitsunami]

Think I did alright. Option topics was straightforward for me, but what caught me off guard is the solar cell. Hopefully didn't lose all 5 marks..did a bad diagram.

 

[Randox]

because the planet (normally this is the satellite) was rotating around the star (central body), and orbital speed = root( Mass central body / radius between the too objects) so it's independent

So you just use the orbital velocity formula and say the mass of the planet is independent. That's what I did

 

[Menomaths]

So you just use the orbital velocity formula and say the mass of the planet is independent. That's what I did

Yeah, the orbital velocity formula isn't on the formula sheet so you must derive it I think

 

[anomalousdecay]

Omgg if this true, then i didnt lose 5 marks for nothing...
I described a solar cell TT

That is exactly what it says in Jacaranda.

 

[Randox]

What was the reason for the person feeling gravity in the circle thingy lol

?

 

[Randox]

Yeah, the orbital velocity formula isn't on the formula sheet so you must derive it I think

Lol I just had it memorized.. V=(root(GM/r))

 

[darkness70]

Thought the exam paper this year was more difficult than past years, but I think I did pretty well

 

[RealiseNothing]

?

I talked about centripetal force.

 

[Randox]

I talked about centripetal force.

Hmm I said centripetal acceleration... I originally said force but then crossed out. Thus is because I used centripetal acceleration in he second past of that qn. Do you think centripetal acceleration is ok?

 

[anomalousdecay]

^
Same. Then relate Fc to Fg and derive the orbital speed.

 

[darkness70]

Hmm I said centripetal acceleration... I originally said force but then crossed out. Thus is because I used centripetal acceleration in he second past of that qn. Do you think centripetal acceleration is ok?

Yeah i think so, acceleration has a direction, which determines the direction of the force.. Force would have been better but I guess it's sort of the same idea.

 

[Dementured]

What was the reason for the person feeling gravity in the circle thingy lol

Centripetal force?

EDIT: Didn't read that it'd had been answered already. Whoops.

 

[Randox]

What did everyone talk about for 6 marker on Einstein?

 

[yasminee96]

The syllabus was amended for 2010 and the photocell dotpoint was changed:
"identify data sources, gather, process and present information to summarise the use of the photoelectric effect in photocells"
Thats why many schools and sources dont really learn about the phototube.
SO i think either answer would be right

Yeah but there's another dotpoint that asks about solar cells in the 3rd section, where semiconductors are spoken about. So they're clearly separate :/