Physics CIE help

[Saladin]

I think the answer is D. Because + the inaccuracy and - the inaccuracy is stll within the 300-350 range. So it is 300.

[nid404]

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

ok...3% of 227.66 is 9.8 approx 10...so the final answer is rounded off to the nearest 10 which is 330

[tmisterr]

thanks nid
 how bout this one? I know the value but how do get the direction?

q36 ATTACHED PAPER

[nid404]

field always from positive to negative...so from Q towards P

[tmisterr]

how do you know when earthed plate is positive and when it is negative? it confuses me!

[nid404]

the other plate is negative, so it is but obv the earthed plate is positive

[cashem'up]

hey guys i have a doubt in physics mcq november 2005 Q7 can someone please show me how its done

[astarmathsandphysics]

s_1=1/2at_1^2
s_2=1/2at_2^2
subtrat
h=1/2a(t_2^2-t_1^2)
a=2h/(t_2^2-t_1^2)

[tmisterr]

field always from positive to negative...so from Q towards P

Thank you once again

[*Hope*]

hey guys! Can u help me out in physics CIE paper1 nov03 Q31? am not able to solve it

[T.Q]

hey guys! Can u help me out in physics CIE paper1 nov03 Q31? am not able to solve it

the total resistance of the circuit is = 4 ohms

find the current across the circuit using I=V/R  I=3A

Find the voltage across 2 ohms resistor  V=6v

SO , the voltage across  3 & 6 ohms resistors are V=6v

using  I=V/R across 6 ohms resistor

I=6/6

I=1A

SO THE ANSWER IS A

[*Hope*]

the total resistance of the circuit is = 4 ohms

find the current across the circuit using I=V/R  I=3A

Find the voltage across 2 ohms resistor  V=6v

SO , the voltage across  3 & 6 ohms resistors are V=6v

using  I=V/R across 6 ohms resistor

I=6/6

I=1A

SO THE ANSWER IS A

how did u get 4 ohms in the 1st place?? and can u tell me which paths to take to get the total resistance??

[T.Q]

how did u get 4 ohms in the 1st place?? and can u tell me which paths to take to get the total resistance??

for the parallel resistors  1/3 + 1/6 = 1/R   , 1/R=1/2 , so R=2

now for the series 2+2=4 for the total circuit 

[*Hope*]

for the parallel resistors  1/3 + 1/6 = 1/R   , 1/R=1/2 , so R=2

now for the series 2+2=4 for the total circuit 

Thanks!!TQ
+rep