Answer:
W = 3934 N , m = 401.43 kg
Step-by-step explanation:
This problem can be solved using the rotational equilibrium relation, where we place the reference system at the pivot point and assume that the counterclockwise turns are positive.
∑τ = 0
F 7 - W 1 = 0
W = F 7/1
W = 562 7
W = 3934 N
W = mg
m = W / g
m = 3934 / 9.8
m = 401.43 kg