Q20 I put A in the exam
Here is my reasoning and my teacher's reasoning
The ball is projected at angle to horizontal and with speed u ms^-1. So it undergoes projectile motion. However it was projected against a circular wall. So it will also undergo circular motion. If you look at the image...
I put A – withdraw the rods.
Its true that rods absorb the neutrons and the question states that the moderator increases the rate of fission. So putting the control the rods further into the reactor core would cause more neutrons to be absorbed while withdrawing them will cause fewer neutrons...
I don't remember studying any of those methods in my class. Plus for all the trial and hsc exam papers I have done, I don't remember seeing any questions on those methods.