The GM tube was about 0.84% I think, the cornea was 70.3% of the eye's power, angle was 10.8, roughly 13 day orbital period for the black holes, and the change in length of the arm was 0.005 times the diameter of the proton (so same order of magnitude as 0.001, but 5x larger)

I got same except didn't know how to do the proton one. Also, 0.84% seemed a little too low to me.

Reply 23

Hiling99

14

Original post by Olivia197

Ok thank you- it's just that I got the power of the cornea greater than the total power.

That's really weird as the total power is 1/f of cornea plus 1/f of whatever the other thing was

Reply 24

Duckington

Original post by Xepheria_

The GM tube was about 0.84% I think, the cornea was 70.3% of the eye's power, angle was 10.8, roughly 13 day orbital period for the black holes, and the change in length of the arm was 0.005 times the diameter of the proton (so same order of magnitude as 0.001, but 5x larger)

for the black hole one, how did you work out the time? it had no mentioning of time and i couldn't see a way to work it out

Reply 25

Olivia197

2

Original post by Hiling99

That's really weird as the total power is 1/f of cornea plus 1/f of whatever the other thing was

I think I read the question wrong- I used about 2cm as the focal length for the cornea and about 5cm as the focal length of the lens by mistake!

Reply 26

Oscar_Ross

3

No mark scheme anywhere?

Reply 27

Historygcse

5

7500000 fo wavelength?

Reply 28

Historygcse

5

Can you not use the hubbles law for the distance measurement??

Reply 29

Amser1417

5

Original post by Historygcse

Can you not use the hubbles law for the distance measurement??

I used red shift and then Hubble's law but I am not sure

Reply 30

distractme

6

I left the 12 days thing in seconds...lol and I got the %of cornea to be like 55% ish?

Reply 31

Historygcse

5

Original post by vuquach99

I used red shift and then Hubble's law but I am not sure

I said the same

Reply 32

distractme

6

Wait no ignore my percentage just realised what I did wrong

And the goggles one?

Refractive index for cornea and water are similar, little refraction.. then. .

Reply 35

Amser1417

5

grade boundary for this paper anyone?

Reply 36

Historygcse

5

Did anyone get around 7500000m for the last question part a mean wavelength

Reply 37

Xepheria_

OP

1

Original post by Duckington

for the black hole one, how did you work out the time? it had no mentioning of time and i couldn't see a way to work it out

You find the time period of the black hole by finding the centripetal acceleration (using the gravitational force from the previous question). Substitute into a = w^2 x r, then rearrange for T.

Wavelength of the gravitational wave was 7,500,000m (from a time period of 0.025s, may be different depending on what you measured).