F4 physics mechanics

(1) Total mass of X and Y = 10 kg
So net force on them = 10 x 2 = 20 N
Thus, total friction on blocks X and Y = 50 - 20 = 30 N
(2) Now, net force on the blocks = 30 N which is the total friction.
Thus, deceleration = 30/10 = 3 m/s2.

2009-09-03 09:10:37 補充：
如果 X and Y 有相同的 mass, 作用於它們的 friction 就相同