Answer:
We can use the concept of buoyancy to solve this problem.
The weight of the metal block in air is equal to the force of gravity acting on it, which is given as 60 Newtons. When the block is immersed in paraffin wax, it displaces a certain volume of wax equal to its own volume, and experiences an upward force due to buoyancy that partially cancels out the force of gravity acting on it.
The buoyant force acting on the block is given by the formula:
buoyant force = weight of fluid displaced
= density of fluid x volume of fluid displaced x acceleration due to gravity
The weight of the metal block in the paraffin wax is then equal to the difference between the weight of the block in air and the buoyant force acting on it.
Let's calculate the volume of the metal block first:
density of metal block = 900 kg/m³
weight of metal block in air = 60 N
acceleration due to gravity = 9.81 m/s²
weight of metal block = density of metal block x volume of metal block x acceleration due to gravity
volume of metal block = weight of metal block / (density of metal block x acceleration due to gravity)
= 60 N / (900 kg/m³ x 9.81 m/s²)
= 0.006536 m³
Now, let's calculate the weight of the metal block in the paraffin wax:
density of paraffin wax = 800 kg/m³
buoyant force = density of fluid x volume of fluid displaced x acceleration due to gravity
= 800 kg/m³ x 0.006536 m³ x 9.81 m/s²
= 51.02 N
weight of metal block in paraffin wax = weight of metal block in air - buoyant force
= 60 N - 51.02 N
= 8.98 N
Therefore, the weight of the metal block when it is immersed in paraffin wax of density 800 kg/m³ is 8.98 Newtons.