2012 VCAA Physics Written examination 1 Suggested Solutions [iTute]

[Phy124]

Well some suggested solutions by Helper of iTute are up, hope you all did well 

Q1a speed =3.0 m/s
Q1b work = 5.4 J
Q1c k = 1.7x10^3 N/m
Q1d impulse = 3.6 Ns

Q2 The 1.2kg has momentum in the opposite direction to the 2.4kg momentum. .: the answer according to conservation of momentum.

Q3 B, the force vectors in B can add to zero.

Q4a 30 N up
Q4b 2.0kg mass attracts Earth, up

Q5a T1=800N
Q5b T2=700N
Q5c speed=6.0 m/s
Q5d Rope 1, accel=1.3 m/s2

Q6a speed=20 m/s
Q6b time=3.5 s

Q7a speed=6.0 m/s
Q7b tangential at P, "down"
Q7c At the bottom string holds the ball as well as changing its direction. At the top the weight of the ball helps to change its direction.

Q8a height=1.2x10^5 m
Q8b weightlessness: zero force of gravity
apparent weightlessness: weightless feeling because of zero reaction force
apparent weightlessness

Elec:
Q1 250 ohms

Q2a I=100mA
Q2b V(R2)=5V
Q2c I=93 mA
Q2d D1: 75%, D2: 67%, D1 is more efficient

Q3a light intensity=10 lux
Q3b R=2000 ohms, connect switching circuit parallel to LDR

Q4a |gain|=250
Q4b inverted, clipped at +/-10V, period=2 ms
Q4c modulation: changes electrical signal to light signal (light intensity variation)
light beam: carrier of signal
demodulation: light intensity variation changes back to electrical signal

Struct:
Q1 tent: pole in compression 212N, B
Q2 Young's modulus stiffest: A
Q3 Force on AlloyB: C
Q4 shows elaastic behaviour over greatest strain range: D
Q5 shows plastic .......: A
Q6 toughest: A
Q7 strain energy: C
Q8 support force 180000N: D
Q9 anchor force 60000N: B
Q10 igloo: arch, strong in compression: B
Q11 shear stress: C
Q12 simply supported beam, bottom in tension: C

Source: http://www.itute.com/board/viewtopic.php?f=6&t=2478

[WhoTookMyUsername]

does anyone have the scanned copy of the exam?

[wicket]

Yo dudes go here

https://www.box.com/s/03edaf2a9b17df9e573b

   

[tphan]

Is it possible to use the standard resistor parallel to the switching circuit with a resistance of 4500 ohms?

[max payne]

Is it possible to use the standard resistor parallel to the switching circuit with a resistance of 4500 ohms?

nah sorry. The question needed the Vout to increase with decreasing light intensity. In a parallel circuit, the voltage across both would be constant.