Q8. This question is good to differentiate A+ students from the rest, you must 1st know the gravity is -10, and then use v2 = u2 + 2as.
Q12. a tricky one, by moving the bottle deeper will increase the pressure. P = hpg
Q14. this question will test whether the student knows density of salt water is higher than water is higher than oil. therefore affects the distance.
Q25. Good question to test concept of optics.
Q26. another tricky one which you need to know clearly which is angle of incidence and which is angle of refraction, both are against the normal.