3B Scientific Device for Archimedes' Principle - Manual

3B SCIENTIFIC® PHYSICS
1
Device for Archimedes' Principle U40875
Operating instructions
04/08 ALF
1 Handle
2 Bucket
3 Cylinder
1. Description
The device for Archimedes' Principle is used to
demonstrate Archimedes' Principle of buoyancy in
liquids. It can also be used to determine the den-
sity of an unknown fluid.
It consists of a bucket with a handle and a hook, as
well as a precisely fitted solid cylinder with a ring.
There are division marks on both the cylinder and
the bucket which allow the user to perform ex-
periments with different volumes. Each division
mark represents one quarter of the total volume.
2. Basic principles
According to Archimedes' Principle, if an object is
immersed in a fluid, the force F
B
exerted on the
object by the fluid is equal to the weight of the
fluid F
W
displaced by the object, F
B
= F
W
.
Archimedes' Principle is valid in fluids as well as in
gases.
Since the volume of fluid V
F
displaced by the object
is just equal to the volume of the object V
K
the
mass of fluid m
F
displaced is the volume of the
object V
K
multiplied by the density of the fluid
ρ.
m
F
=
ρ V
K
(1)
The weight of the displaced fluid F
W
is this mass m
F
multiplied by the acceleration due to gravity g.
F W
m g F
⋅ =
(2)
Therefore the buoyant force F
B
is given by the fol-
lowing formula
F
B
=
ρ g V
K
(3)
The density
ρ of an unknown fluid can therefore be
calculated by the formula:
V
F
B = ρ
(4)