# physics exam (1 Viewer)

#### Forbidden.

##### Banned
As long as something travels at relativistic speeds you should know that its mass will increase, so it should be 1.37 rather than 0.37.

morjoel said:
Hmm for that torque question i used the radius which was 0.1m

Which means T = f x d
T = mass(don't remember it) x 9.8 x 0.1

Except for some reason i didnt get 192 coils i got exactly 200.

#### gizmo99

##### New Member
thehootman said:
Yeah thats what i did. It would be riduculous if it was .37% as that would yeild a velocity very low. Also, you get full marks if it is evident that you read it wrong but had correct method.

OVerall i found the exam pretty easy
No I'm very sure it said 0.37%

#### Steth0scope

##### Member
the question said 0.37% which 0.37/100

#### Forbidden.

##### Banned
the question said 0.37% which 0.37/100
They said a 0.37% increase in mass.

I AM NOW GOING TO SCREAM IN HYSTERIA AND ANGER SIMULTANEOUSLY.

#### Steth0scope

##### Member
im not saying sub in 0.37 or wateva

I am saying rest mass = 1.00
Relativistic mass = 1.0037 NOT 1.37 because it said 0.37% not 37%

#### farahodish

##### Member
why THE F#\$\$ would it say .37%?! THATS SO NEGLIGIBLE THAT ITS NOT EVEN FUNNY!!!!!!!

swear you're all seeing things. *curls up into denial bubble*

ARE YOU TESTING EFFING PHYSICS, OR FREAKING READING SKILLS WITH THAT QUESTION?!?!?!?!?!?!?

IF I WANTED TO SIT AN EXAM THAT TESTED ME ON MY EFFING ABILITIES TO NOTICE THINGS LIKE THAT I"D SIT AN EFFING IQ TEST!!!!!!!!!!!!

*BOMBS
WHOEVER
WROTE
PHYSICS
EXAM'S
FAMILY
..
..
..
MULTIPLE TIMES*

grrrrrrrrrrrrrrrrrrrr :burn: :burn:

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#### Forbidden.

##### Banned
This is what makes the Exam Thoughts forum so good.
We see each other's mistakes and errors, we scream and complain.
Excellent way to celebrate the end of the HSC.

#### James747

##### Member
YAY! I put 37% first, then I went back and changed it!!!!! YAYAYAYAYAY!

I reckon the exam wasn't too difficult this year, though the maths was much harder and required mixing two equations together. The high mark questions weren't too hard though!

Anyway, what did you guys get for the last q? It was asking the significant that all the gradients were the same... :S

#### mzduxx2006

##### Member
omg i feel ur pain :'(

#### mzduxx2006

##### Member
omg i feel ur pain :'(

#### James747

##### Member
thehootman said:
Yeah thats what i did. It would be riduculous if it was .37% as that would yeild a velocity very low. Also, you get full marks if it is evident that you read it wrong but had correct method.

OVerall i found the exam pretty easy
I don't think you'll get marks if you read it wrong. You get marks for the equation and substituting the values correctly! Substituting 37% instead of 0.37% is not correct and so I highly doubt you'll get marks for that

#### twilight1412

##### Member
diameter you had to use keplers 3rd law

i used 37% =P
ended up with a velocity like 2x10^8

#### Steth0scope

##### Member
for the last question i said 2 things .. it shows that the energy of the electrons emitted is directly proportional to the frequency of the photon...and another significance is the possibility of being able to calculate planck's constant from rise/run ?

#### twiig

##### New Member
morjoel said:
Hmm for that torque question i used the radius which was 0.1m

Which means T = f x d
T = mass(don't remember it) x 9.8 x 0.1

Except for some reason i didnt get 192 coils i got exactly 200.

Mass weighs 0.2kg and turns through one-quarter of the circumference of the circle

torque= f x d
= m x a x (0.25 x 0.2 x"pi")
= 0.2 x 9.8 x (0.25 x 0.2 xpi)
= 0.307 Nm

torque of motor = torque of weight
n x 0.1 x 0.01 x 1 x 1= 0.307 [i think b=0.1, a=0.01, I=1]
n=307 turns

thats what i remember........may be wrong

#### twilight1412

##### Member
i think your wrong there twiig

torque is perpendicular distance so its the radius =)
so torque = 0.1 x 0.2 = 0.02

therefore its 20 turns which is more logical

#### Bedsey90

##### New Member
twiig said:
Mass weighs 0.2kg and turns through one-quarter of the circumference of the circle

torque= f x d
= m x a x (0.25 x 0.2 x"pi")
= 0.2 x 9.8 x (0.25 x 0.2 xpi)
= 0.307 Nm
mate i think that 'd' is just the perpendicular distance so its just the radius (0.1m). could be rong tho. i got 296 coils i think

#### nealos

##### Member
Nosviper said:
I got different answers to you. I could swear for the first page it asked for the horizontal velocity at P. THats what I found anyway

1) A
2) A
3) B
4) D
5) D
6) D
7) C
8) B
9) C
10) A
11) D
12) D
13) C
14) A {key word = property}
15) A
can some one tell me what they put for multi choice q 7c

#### twilight1412

##### Member
lol i agree with twiig on the second part

but i agree with bedsey on the first part =)

i have the best of both worlds lol

#### twilight1412

##### Member
nealos said:
can some one tell me what they put for multi choice q 7c
can you at least tell us what question it was?

chances are it is D =D
there was alot of them

#### chukatsung

##### New Member
morjoel said:
Hmm for that torque question i used the radius which was 0.1m

Which means T = f x d
T = mass(don't remember it) x 9.8 x 0.1

Except for some reason i didnt get 192 coils i got exactly 200.

lol
i got 200 turns as well, didnt know how i got it tho,
i forgot XD