Experiment: to demonstrate Archimedes principle with a worked example
Experiment: To demonstrate Archimedes principle:Procedure1. Pour water into an overflow can (eureka can) until it starts to flow out then wait until it stops dripping2. Tie a suitable solid body securely and suspend it on a spring balance. Determine weight in air.3. Lower the body slowly into the overflow can while still attached to the spring balance then read off its weight when fully submerged.4. Weigh the displaced water collected in a beaker. Record your readings as follows;Weight of body in air = W1Weight of body in water = W2Weight of empty beaker = W3Weight of beaker and displaced liquid = W4Upthrust of the body = W1 –W2Weight of displaced water =W4 –W3DiscussionThe upthrust on the solid body will be found to be equal to the weight of displaced water therefore demonstrating the Archimedes principle.ExampleA block of metal of volume 60 #cm^3# weighs 4.80 N in air.Determine its weight when fully submerged in a liquid of density 1,200 #kgm^-3#.Solution:Volume of liquid displaced = 60# cm^3# =# 6.0 times 10^-5 m^3#.Weight of the displaced liquid= volume × density × gravity =v × ρ × g= #6.0 times 10^-5 times 1200 times 10#= 0.72 NUpthrust = weight of theliquid displaced.Weight of the block in theliquid = (4.80 – 0.72) = 4.08 N.