Write the differences between the following.

i. Force and pressure
ii. Archimede's principle and the law of flotation
iii. Upthrust and pressure
iv. Density and relative density

i. Force and pressure

It is the product of mass and acceleration.It is the total force applied per unit area.
Force = m.aPressure = F/A
Its SI unit is Newton (N).Its SI unit is Pascal (Pa).

ii. Archimede's principle and the law of flotation.

Archimede's principle
Law of flotation
It states that when a body is partially or totally immersed in a liquid, it experiences the upthrust equal to the weight of the liquid displaced by it.It states that a body floats on a liquid if it can displace the liquid equal to its own weight.
It is the cause of the law of flotation.It is a special case of Archimede's principle.

iii. Upthrust and pressure.

The resultant upward thrust exerted by fluid is called upthrust.The total force applied per unit area is called pressure.
Upthrust = m.gPressure = F/A
Its SI unit is N.Its SI unit is Pa.

iv. Density and relative density.

DensityRelative density
The total mass per unit volume is called density.The ratio of the density of substance and density of pure water at 40C is called relative density.
Density = m/VR. density = Ds / Dw at 40C
Its unit is kg/m3.It is unitless.