Author Topic: physics AS HELPPP  (Read 1023 times)

Offline halosh92

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physics AS HELPPP
« on: March 07, 2010, 03:15:17 pm »
physics cie AS
2006 jun paper 1
Q 1
Q9
Q12
Q15
Q17
Q18
Q24
Q33

thx ;D ;D ;D ;D ;D ;D ;D ;D ;D
everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline astarmathsandphysics

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Re: physics AS HELPPP
« Reply #1 on: March 07, 2010, 03:58:28 pm »
Will have to do it when I get home

Offline tmisterr

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Re: physics AS HELPPP
« Reply #2 on: March 07, 2010, 05:09:39 pm »
Q1 vector quantities have both magnitude(size) and direction. answer is A (displacement and Acceleration)
Q12 from law of conservation of momentum, moment before=momentum after. Call speed after momentum x and their combined mass after collision will be m+3m=4m. take one direction as positive and the other negative
so m*-2v+3m*v=3m*x
-2mv+3mv=4mx
mv=4mx
x=v/4 which is A
Q15 length of bar is 2.4m long. Half the distance is 1.2 m long so distance from 300N to pivot is 0.4.
Clockwise moment is 300*0.4=120. Anticlockwise moment is 200*0.8=160. for it to be in equilibrium CM=ACM so you need to add a torque of 40Nm in the clockwise direction for it to equal 160. Answer is A.
Q17 v2=u2+2as. from the infromation 02=102+2*10*a
a=-5ms-2
now u is 30 and s is asked
02=302-2*-5*s
s=90 Answer is D
Q18 potential energy=mass*gravity*height
mg=4 so PE= 4*30=120J answer is A
Q24 intensity is directly proportional to Amplitude2*frequecy2 knowing this will help you solve. you can just replace values from the first graph into the equation, find and find k, and use it to find the amplitude and frequency of the second graph. Its a little hard to explain via writing but answer should be B
Q33 Answer is B. Use the equation Vout=Vin*R1/(R1+R2). Vin to the top two resistors is 12 and to the bottom two is also 12 since they are connected in parallel. Voltage across 500 ohm resistor (voltage at X) will be 4 and across 2000 ohm resistor (voltage at Y)is 8. the difference is 4.

Offline halosh92

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Re: physics AS HELPPP
« Reply #3 on: March 07, 2010, 05:48:34 pm »
Q1 vector quantities have both magnitude(size) and direction. answer is A (displacement and Acceleration)
Q12 from law of conservation of momentum, moment before=momentum after. Call speed after momentum x and their combined mass after collision will be m+3m=4m. take one direction as positive and the other negative
so m*-2v+3m*v=3m*x
-2mv+3mv=4mx
mv=4mx
x=v/4 which is A
Q15 length of bar is 2.4m long. Half the distance is 1.2 m long so distance from 300N to pivot is 0.4.
Clockwise moment is 300*0.4=120. Anticlockwise moment is 200*0.8=160. for it to be in equilibrium CM=ACM so you need to add a torque of 40Nm in the clockwise direction for it to equal 160. Answer is A.
Q17 v2=u2+2as. from the infromation 02=102+2*10*a
a=-5ms-2
now u is 30 and s is asked
02=302-2*-5*s
s=90 Answer is D
Q18 potential energy=mass*gravity*height
mg=4 so PE= 4*30=120J answer is A
Q24 intensity is directly proportional to Amplitude2*frequecy2 knowing this will help you solve. you can just replace values from the first graph into the equation, find and find k, and use it to find the amplitude and frequency of the second graph. Its a little hard to explain via writing but answer should be B
Q33 Answer is B. Use the equation Vout=Vin*R1/(R1+R2). Vin to the top two resistors is 12 and to the bottom two is also 12 since they are connected in parallel. Voltage across 500 ohm resistor (voltage at X) will be 4 and across 2000 ohm resistor (voltage at Y)is 8. the difference is 4.


thankyouuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu soooooooooooooooooo muchhhhhhhhh! that wasvery gd! ;) ;D ;D
everyday we wake up is a miracle, then how do we say miracles dont happen?????

nid404

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Re: physics AS HELPPP
« Reply #4 on: March 08, 2010, 04:33:20 pm »
thanks tmisterr

Offline halosh92

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Re: physics AS HELPPP
« Reply #5 on: March 08, 2010, 06:33:44 pm »
2005 nov paper 1:
Q6
Q7
Q8
Q12
Q21
Q31
everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline astarmathsandphysics

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Re: physics AS HELPPP
« Reply #6 on: March 09, 2010, 07:52:54 am »
6)B acceleration of gravity is constant 9,8
7)C use s=ut+1/2at^2 twice
s_1=1/2at_1^2
s_2=1/2at_2^2
subtract
s_2 -s_1 =1/2at_2^2 -1/2at_1^2
h=1/2a(t_2^2 -t_1^2)
a=2h/(t_2^2 -t_1^2)
8)A zero speed at start then constant force means constant acceleration hence gradient

Offline astarmathsandphysics

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Re: physics AS HELPPP
« Reply #7 on: March 09, 2010, 08:02:09 am »
12)moments about P
10*0.6+100*0.1=20x+0.4*20
16=20x+8 so x=0.4
D
21)Y=Fl/Ae
e=Fl/AY
half the diameter means 1/4 of area so 1/4/1/4=1 and extension is not changed
C
31)F=Eq=V/d*q=200/5*10-3 *1.6*10^-19 =6.4*10-15
A

Offline tmisterr

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Re: physics AS HELPPP
« Reply #8 on: March 09, 2010, 02:54:15 pm »
ur welcome :)