Q1
http://img187.imageshack.us/img187/5202/f1xj9.th.png
M is on the point of sliding:
0 = MA g - T => T = MA g ... (1)
0 = T - (0.35)(150 g) ... (2)
Substitute (1) into (2) : MA = (0.35)(150) = 52.5 kg.
http://img187.imageshack.us/img187/787/f2co6.th.png
is the answer 398.5 kg...