(1) As can be seen from the figure, pulley B is crown block; The pulley c is crown block; Pulley d is a moving pulley.

(2) Because the gravity on the counterweight A is 1200N, if the counterweight A is just pulled up, the pulling force at the DE end is F=600N.

Balance in horizontal position. ∴ From the lever balance condition: F OE = F 1 OH, so F=240N.

(3) The vertical downward pulling force acting on point H is F 2 =260N, which is obtained from the lever equilibrium condition: F 0 10 OE = F 2 OH, so f 010 = 650 N..

According to 650N=(G object +G motion) /n, that is, 650N=( 1200N+G motion) /2, so g motion = 100N.