Thread: mechanics pulley problem

i tried but got answer in negative i.e -1.4ms^-2 . this is how i solved T-5g=5a
8g-2T=8*0.5*a but i keep on getting negative answer need help

Your answer is correct, assuming that positive acceleration of the 5Kg mass means it rises and negative acceleration means it falls. What do you get for tension in the cable - if it's between 4g and 5g newtons then the 5Kg mass falls while the 8Kg pulley rises.

well its either negative acceleration the entire motion whether rising or falling or it is positive but we have to assume acceleration positive