Physics doubts!

[tanmaydube]

Paper 3 October November 2001
5(a) can anyone please explain what to do?
Thank you!

 

[haochen]

link please

 

[tanmaydube]

http://www.xtremepapers.me/CIE/Cambridg ... 1_qp_3.pdf

 

[yousef0074]

experiment 1: 250g--->10500J
1g ---> x x= 42J needed for a 10 degree celsius temperature rise


energy needed for a 100 degree celsius rise: 42J---->10
x----->100 x=420J

experiment2: 15g--->33900J
1g----> x x=2260J

difference= 2260-420= 1840J

 

[davirus]

Hello guys am srry i just need to ask what is the critical angle i rlly suck at the critical angle plzz help and thx

 

[yousef0074]

it's the angle of incidence in the higher optically dense medium where angle of refraction makes 90 degrees with the normal

 

[medevil]

when an incident ray is going from denser medium to lighter medium (such as glass to block)> If this ray causes the angle of refraction to be 90 degrees to the normal and along the edge of the block, then that angle is critical angle
If the incident ray goes beyond the critical angle all the light rays will be reflected back to the same medium back into glass block(total internal reflection) hope this helped.

 

[ajmanutd]

Hello guys am srry i just need to ask what is the critical angle i rlly suck at the critical angle plzz help and thx

critical angle is d angle above which total internal reflection will take place..
if d angle of incidence is = to d critical angle the ray of light will refract 90 degrees from the normal..

hope it helped..

 

[davirus]

thx alot guys u rlly helped me but isnt there an equation to find a critical angle? cuz how suppose i find out if incedent angle greater than critical angle?
Thx

 

[medevil]

i dont think we have the equation in our syllabus u jus have to know that if the light rays are reflected back into the glass block again it is more than the critical angle
if u refer to the digram in this site it will be clearer
http://www.physicsclassroom.com/class/refrn/u14l3c.cf
:lol:

 

[medevil]

i dont think we have the equation in our syllabus u jus have to know that if the light rays are reflected back into the glass block again it is more than the critical angle
if u refer to the digram in this site it will be clearer
http://www.physicsclassroom.com/class/refrn/u14l3c.cf
:lol:

 

[unplugged]

i dont think we have the equation in our syllabus u jus have to know that if the light rays are reflected back into the glass block again it is more than the critical angle
if u refer to the digram in this site it will be clearer
http://www.physicsclassroom.com/class/refrn/u14l3c.cf
:lol:

The refractive index = sin angle of incidence / sin angle of refraction = speed of light in a vacum / speed of light in medium.
So the angle of incidence in this case will be the 90 because this is the angle of the ray that was trying to get out of the glass.
so Refractive index = sin 90 / sin(critical angle). sin(critical angle) = 1/ Refractive index