Answer
3,528 N
Step-by-step explanation
density = mass/volume
ρ = m/v
∴ m = ρv
 = 4000 × 0.09
 = 360 Kg
Weight is defined as the force that acts on a body and is directed towards the center of the earth. 
Weight = mass × acceleration due to gravity
W = mg  Where g = 9.8 m/s²
W = 360 × 9.8
 = 3,528 N