Kindly have a look at the attached image for the related question.
I've solved (i) to get the following values...
a= 2.5 ms^-2
T= 3.75 N
I want to inquire about part (ii)
What I want to know is that since acceleration of A was 2.5 then the acceleration of B should be -2.5 ... no?
I ask this because, for part (ii) I've got the correct answer of 'mass' by using
But if I use -2.5 then the answer comes out to be m=0.5 kg.
What am I doing wrong?