IGCSE PHYSICS DOUBTS HERE !!!!

[elemis]

Can someone please explain to me how do you solve Q38 in this paper?
http://www.xtremepapers.me/CIE/Cambridge%20IGCSE/0625%20-%20Physics/0625_w10_qp_11.pdf

Every 70 seconds the count rate will half.

If you started off with a count rate of 100 the 70 seconds EARLIER the count rate would be 140.

Hence, if you have a count rate of N the count rate 70 seconds EARLIER would be 2N.

[NotAbod]

http://www.xtremepapers.me/CIE/index.php?dir=Cambridge%20IGCSE/0625%20-%20Physics/&file=0625_w05_qp_6.pdf
Question 2 (a)  and (C)please
and: http://www.xtremepapers.me/CIE/index.php?dir=Cambridge%20IGCSE/0625%20-%20Physics/&file=0625_s06_qp_6.pdf
Question 1(d) and explain it please

help as soon as possible, my exam is 2mrw!
Thanks in advance

[**RoRo**]

Every 70 seconds the count rate will half.

If you started off with a count rate of 100 the 70 seconds EARLIER the count rate would be 140.

Hence, if you have a count rate of N the count rate 70 seconds EARLIER would be 2N.

Thank you and I apologize for the late reply!

[NotAbod]

http://www.xtremepapers.me/CIE/index.php?dir=Cambridge%20IGCSE/0625%20-%20Physics/&file=0625_w05_qp_6.pdf
Question 2 (a)  and (C)please
and: http://www.xtremepapers.me/CIE/index.php?dir=Cambridge%20IGCSE/0625%20-%20Physics/&file=0625_s06_qp_6.pdf
Question 1(d) and explain it please

help as soon as possible, my exam is 2mrw!
Thanks in advance

Help someone :s my exam is after 3 hours!!!!!!

[~ Miss Relina ~]

hello plz anyone can help with the refractive index issue as i noticed that there ws a conflict between
May/June 2005 Q6
May?june 2009 Q 8

[**RoRo**]

hello plz anyone can help with the refractive index issue as i noticed that there ws a conflict between
May/June 2005 Q6
May?june 2009 Q 8

The refractive index is different every time, it depends on the frequency of light that passes through what sort of material, it'll be given to you, or you'd have to calculate it using the formula(s) that you've learnt.

[~ Miss Relina ~]

The refractive index is different every time, it depends on the frequency of light that passes through what sort of material, it'll be given to you, or you'd have to calculate it using the formula(s) that you've learnt.

the problemis that each q asks to bring the same thing but each one used different way of refractive index one used sin(i)/sin(r)and the other used sin(r)/sin(i) even both moved from the more dense to less dense so why

[**RoRo**]

the problemis that each q asks to bring the same thing but each one used different way of refractive index one used sin(i)/sin(r)and the other used sin(r)/sin(i) even both moved from the more dense to less dense so why

The correct formula that you can use in both cases is Sin i/Sin r, it's acceptable in both the questions.

[~ Miss Relina ~]

The correct formula that you can use in both cases is Sin i/Sin r, it's acceptable in both the questions.

but if u apply this in may 2009 it will not work

[**RoRo**]

but if u apply this in may 2009 it will not work

Here's what the MS says:
n = sin i / sin r  OR  n = sin r / sin i  OR  1.49 = sin i / sin 35 C1
  (allow 1.49 or refractive index instead of n in any of above)
  58.719° to at least 2 s.f.  Allow 58.71°

[~ Miss Relina ~]

Here's what the MS says:
n = sin i / sin r  OR  n = sin r / sin i  OR  1.49 = sin i / sin 35 C1
  (allow 1.49 or refractive index instead of n in any of above)
  58.719° to at least 2 s.f.  Allow 58.71°

i know that but plz if u measure the angles and try to put it in equation of n = sin i / sin r answer will not be 58.7

[~ Miss Relina ~]

here is another question

[**RoRo**]

i know that but plz if u measure the angles and try to put it in equation of n = sin i / sin r answer will not be 58.7

Ohhh, I got you, yea, I get something like 22.6 - I'm sorry, I can't figure out the reason behind this, but as far as I remember when you have to find the refractive index, you use the formula, n=sin i/sin r

[~ Miss Relina ~]

Ohhh, I got you, yea, I get something like 22.6 - I'm sorry, I can't figure out the reason behind this, but as far as I remember when you have to find the refractive index, you use the formula, n=sin i/sin r

me too hope somebody help  soon exam after tommoroow

[~ Miss Relina ~]

here is another question

and this one anyo ne know how to do it