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Question 3 - to - 5

EST 1) State Archimede's principle. by mass ofme splacid fid 2) Use Archimedes' principle to prove the following: "When a body is floating on a liquid, it displaces a weight of liquid equal to its own weight." 3) How would you determine the density of an irregularly shaped rock? 4) Lead has a greater density than iron, and both are denser than water. Is the buoyant force on each one the same? Explain. 5) A beaker resting on a scale contains a fluid. If an object is submerged in the fluid, how would you find the increase in the reading of the scale?

Answer 1

(3) To determine the density of irregularly shaped rock, first we have to find its mass using a balance. Then immerse it in water and find the volume of water displaced by the rock. That will be the volume of the rock. Now, divide mass by volume to find density of the rock.

(4) Buoyant force on any object is equal to the weight of liquid displaced by the object when it is immersed in the liquid. Now, if volume of liquid displaced by Lead and Iron is same, then buoyance force on both will be same. If volume displaced is different then buoyance force will also be different.

(5) When an object is immersed in a liquid, it will exert an upward buoyance force on the object. Now, by newton's third law, the object also exerts downward force on the liquid which will be equal in magnitude. Now, the reading will be increased by the amount which will be equal to this magnitude of buoyance force.