- #1
Taniaz
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- 1
Homework Statement
A block hangs by a cord from a spring balance and is submerged in a liquid contained in a beaker. The beaker in turn rests on a kitchen scales. The mass of the beaker is 1 kg, the mass of the liquid is 1.5 kg. The spring balance read 2.5 kg and the kitchen scales reads 7.5 kg. The volume of the block is 0.0030 m^3.
(a)What is the mass per unit volume of the liquid?
(b) What will the spring balance and the kitchen scales read if the block is pulled up out of the liquid?
Homework Equations
Fb = weight of displaced liquid = ρgV = mg
mass of displaced liquid=mass of block
Volume of displaced liquid = volume of block
The Attempt at a Solution
For part a I'm a little confused with respect to the masses shown by the scales, how is the kitchen scales showing such a big reading? Where is it coming from? Part a wants the density, I already know the volume of the block = volume of displaced liquid, just need to figure out the mass.
Not sure of part b.
I have another hunch. If we subtract the mass of the beaker and that of the liquid from the kitchen scales mass we get 7.5-(1.5+1) = 5kg and I presume this is the mass of the block and the displaced liquid? Then we subtract the mass of the block which is 2.5 kg as shown by the spring balance I presume from 5 kg to get 5-2.5 = 2.5 kg as the mass of the displaced liquid?
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