urgent-newton's laws I need help with this question(halliday, resnick and walker, fifth edition, chapter 5 , question 14): PS: I cant draw the figure so I am explaining it as much as possible. 3 wooden blocks are pushed across a frictionless floor.The blocks have masses of 5kg, 2kg and 10kg. The 3 blocks are joined or pressed against each other in the above order. In other words they are moving together. A force of F acts on the first block i e 5 kg. The question asks to find the acceleration and force on each block? I have considered the 3 blocks as 3 different system. Considering motion only in horizontal direction, I would say I got the following equations: F-f(force on 1st block due to second)=5a1(accn of the 1st block) f(force on 2nd block due to 1st)-(force on 2nd block due to 3rd)= 2 a2(acc of 2nd block) f(force on 3rd due to 2nd)= 10 a3 adding all the 3 equations and cancelling the action-reaction forces, I got F= 5a1+2 a2+10 a3 The question now asks to rank the blocks accroding to their acceleration and the total mass accelerated by 1) F. I have no clue how to proceed from here. Pls can someone help. I have seen a similar problem of 2 blocks , and the author assumed common acceleration for both the blocks by considering them as one system , and then for each block found the net force from free bodied diagram which should be equal to the mass of the individual block*common acceleration. My question: why is this not the case in the above question? If it were a case it why would the ist question ask to rank the blocks in terms of their acclerations? I am so confused.