cssa seem to have a tendency of giving dodgy solutions, they have lots of problems in chemistry and physics as wellCSSA's answer to their 2023 Adv paper Q28b is wrong. They should have checked ln(16/9)-1 is negative and so the distance is ln(9/16)+1 (or written as ln(9/16) - -1 as question said to write it as ln(a/b)-c)
Checking doesn't seem to be CSSA's strong point because in the CSSA solutions for their 2023 Ext.2 paper Q16c there are actually 2 answers 219.1m/s OR 223.5m/s. They arise from the equation
View attachment 39610
In CSSA's solution the absolute value blissfully disappears and then they only get 1 answer 219.1m/s.
I was not so careless and put my solutions here for comparison and you will see how I got the 2 solutions: https://4unitmaths.com/cssa2023e2-tywebb.pdf