Physics 2007 JAMB Past Questions - Question 34: A piece of iron weighs 250N in air and 200N in a liquid of density 1000kgm.the volume of the iron is

Correct Answer

D

Explanation

To find the volume of the iron, you can use Archimedes' principle, which states that the buoyant force on an object submerged in a fluid is equal to the weight of the fluid displaced by the object. In this case, the iron is submerged in a liquid of density 1000 kg/m³.

The weight of the iron in air is 250 N, and its weight in the liquid is 200 N. The difference in weight is due to the buoyant force.

Buoyant force (F_b) = Weight in air - Weight in liquid
F_b = 250 N - 200 N
F_b = 50 N

Now, you can find the volume of the iron using the formula for buoyant force:

F_b = ρ_fluid * V * g

Where:
F_b is the buoyant force (50 N)
ρ_fluid is the density of the liquid (1000 kg/m³)
V is the volume of the iron (which we want to find)
g is the acceleration due to gravity (approximately 9.81 m/s²)

Rearrange the formula to solve for V:

V = F_b / (ρ_fluid * g)

V = 50 N / (1000 kg/m³ * 9.81 m/s²)
V ≈ 0.0051 m³

So, the volume of the iron is approximately 0.0051 cubic meters.