1. ARCHIMEDES’PRINCIPLE

3. Its S.I Unit is kg/meter cubeFUNDAMENTALS

4. Density formula Units of Density can be found using Density = Mass m Volume v Units g/ml, g/cm3, g/cc Remember 1 ml = 1 cm3 = 1 cc

6. Since it is a ratio it has no unit

8. We know that density of water is 1gm/cm cc RELATIVE DENSITY of a substance But how to prove this? Density of substance = Density of water at 4C Density of substance = 1gm/cm cube Density of substance =

9. Interesting fact Archimedes' Principle is named after “ARCHIMEDE’S OF SYRACUSE "who first discovered this law

10. Archimedes’ Principle Archimedes Principle states that when a body is partially or completely immersed in a fluid, it experiences an apparent loss in weight due to upthrustand this apparent loss in weight is equal to the weight of the fluid displaced by the immersed part of the body Upthrust means Buoyant force

11. What is BUOYANCY and UPTHRUST? What is BUOYANCY and UPTHRUST? Or upthrust

12. BOUYANT FORCE or UPTHRUST When a body is immersed partially or completely inside a fluid it experiences an upward force called the buoyant force

13. Buoyancy The property of the fluids to apply buoyant force is called BUOYANCY

16. Buoyant force =apparent loss in weight-true weight(w1)

17. Materials required for verifying Archimedes principle are: Verify Archimedes principle SPRING BALANCE STONE EUREKA CAN BEAKER

18. Verifying Archimedes’ principle Take an Eureka can and fill it up to its spout. Take a stone and suspend it with the hook of the spring balance.Note the weight of stone in air.Let it be w1. Now immerse the stone inside water in the Eureka can.the water overflows through the can.Collect this overflowing water in the beaker. Now also note the reading in the spring balance.Let it be w2

19. This w2 will be less than w1 due to upthrust provided by water.Apparent loss in weight due to upthrust will be (w1-w2) Measure the weight of water collected in the beaker , which in fact is the weight of water displaced by the stone . On comparing we will found that the loss in weight (w1-w2 )is equal to the weight of the water displaced by the stone.Hence the Archimedes’principle is verified. It states that when a body is partially or completely immersed in a fluid, it experiences an apparent loss in weight due to upthrust and thisapparent loss in weight is equal to the weight of the fluid displaced by the immersed part of the body

21. Principle of Floatation A body floats in a liquid if the weight of the body is equal to the weight of the liquid displaced by it

26. Where will they “float?” Object A: density= 0.8 g/cc Object B:density= 0.95 g/cc Object C:density= 1.1 g/cc oil density= 0.9 g/cc Object D:density= 1.3 g/cc Object E:density= 4.0 g/cc fresh water density= 1.0 g/cc salt water density= 1.2 g/cc

27. Applications of Archimedes’ principle Ships and submarines are designed on the basis of this principle

28. How does a steel ship floats ?

29. A ship is hollow at the bottom because of which its average density is lees than that of water so the ship is able to displace water equal to its weight and hence it floats.

30. How can a submarines float or submerge in water?

31. Submarines have ballast tanks at its basement. When it is to be submerged,these tanks are filled with sea water.As a result its weight becomes more than the weight of water displaced.So it submerges

32. If the submarine has to come up,the tanks are emptied out ,so the weight of the submarine decreases in comparison to the weight of the water displaced and the submarine rises up to the surface

33. The fishes Some species of fishes have swim bladder. When fishes want to rise they fill this bladder with gases diffused from their own body. Thus becoming lighter and to go down they empty their bladder thereby increasing their density and hence manage to sink

35. Hydrogen and Helium filled balloons and hot air balloons tend to move upwards because the density of hydrogen is about 1/4th of the air. The upward force is more than the downward force of the balloon and hence it rises upwards till the density of both becomes same

36. THE END