Answer:
Force of buoyancy is given by
Fb = Weight of displaced water
= mg
But, m=density x volume
= ρV g
where ρ = density of the water
V = volume of displaced water = volume of block
g = acceleration due to gravity
Given that,
V = 50 cm3
g = 981 cm/s2
ρ = 1 g/cm3
Fb = 1*50*981
= 49050 dyne
= 0.49 N