Physics CIE help

[astarmathsandphysics]

No you cant

[sweetie]

hey,
cud u help me with Q14, 19, 35 and 36 of nov02 ( AS cie)

[astarmathsandphysics]

Will have to be in morning
v late here

[astarmathsandphysics]

14 moments about 40 mark 10*100-20*60+50*x=0
1000-1200+50x=0 so x=4
4cm from 40 point going clockwise ie 44cm mark
19.PE=mgh=m*9.8*200=1960m
0.6*1960m=1176m
1/2mv^2=1176m
c^2=2376
v=sqrt(2352)=48.5 C
35.D decreas since more of the voltage is across the variable resistor and nearer to Y cos resistances must remain in proportion
36.2/3V voltage at x is 2/3 and voltage at y is 4/3

[sweetie]

14 moments about 40 mark 10*100-20*60+50*x=0
1000-1200+50x=0 so x=4
4cm from 40 point going clockwise ie 44cm mark
19.PE=mgh=m*9.8*200=1960m
0.6*1960m=1176m
1/2mv^2=1176m
c^2=2376
v=sqrt(2352)=48.5 C
35.D decreas since more of the voltage is across the variable resistor and nearer to Y cos resistances must remain in proportion
36.2/3V voltage at x is 2/3 and voltage at y is 4/3

thanx...
but cud u xplain 14 in more detail??

[astarmathsandphysics]

Clockwise and anticlockwise opposite signs. You must be careful here

[sweetie]

but i think the weight of the rule as well as the 20g mass are acting in a clockwise direction, so same sign.........

[astarmathsandphysics]

The 20g mass is attached to a string pulling the right hand side of the ruler up so anticlockwise

[sweetie]

oops, i got it  ...

cud u help me in Q. 37,32,21,18,12 and 3 of may02..........

[astarmathsandphysics]

 37,32,21,18,12 and 3 of may02....
37. A - V is constant E=V=d
32.P=V^2/R so R=V^2/P=240^2/100=576
originarl R=576/16=36 A
21.total mass is now 3pV in same volume so 3 times the mass occupies the same volume anddensity is 3 times bigger D
18. GPE+KE=work done against friction +KE
5+50=10+KE
KE=45 B
12.weight=upthrust+drag>upthrust D
3.only A m/s=sqrt(m/s^2 *m)=m/s

[*Hope*]

hey astar wat about questions 9,11(why not D) of the same year? Thanks in advance

[astarmathsandphysics]

repeat the paper and year

[sweetie]

 for Q21 the ms says A  
and can u xplain Q18 in more detail plz.......

[nid404]

Q18)

k.e+p.e at Q = k.e + work done against friction
55=k.e+10
k.e=45kJ  B

[tmisterr]

A student makes measurements from which she calculates the speed of sound as 327.66ms–1.
She estimates that her result is accurate to ±3 %.
Which of the following gives her result expressed to the appropriate number of significant figures?
A 327.7ms–1 B 328ms–1 C 330ms–1 D 300ms–1