Measuring
USING MEASURING TOOLS TO MAKE
QUANTITATIVE OBSERVATIONS
We already learned how to measure:
MASS
the measure of
the amount of
matter in an
object
VOLUME
the measure of
the space
occupied by an
object
mass of 3 oranges = 300 g
mass of the bag of apples = 3 kg
What is the volume of
this rectangular solid?
Don't forget to write the
unit of measurement.
Volume of Rectangular Solid = length x width x height
3
Volume = 45 cm x 25 cm x 15 cm = 16,875 cm
What is the volume of the stone
in the graduated cylinder?
Don't forget to write the unit of
measurement.
Water Displacement Method:
Volume of stone = Final volume - Starting volume
Starting volume of water = 150 ml
Final volume (water + stone) = 180 ml
Volume of stone = 180 ml - 150 ml = 30 ml
Now let's study
DENSITY
The density of a
substance is its mass
per unit volume.
It describes how closely
packed the particles are
in that substance.
Density
determines if an
object will sink
or float in
water.
Float or Sink?
Remember:
density of water = 1 g/ml
density of object < 1
FLOAT
density = 1
NEITHER FLOAT NOR SINK
density > 1
SINK
Bouyant Force
is the upward force exerted on objects
submerged in fluids
depends on the density of the fluid in which the
object is submerged,
If the mass of the stone is 50 g and its volume is 30ml, what is
its density? Don't forget to write the unit of measurement.
density = mass
volume
mass = 50 g
volume = 30 ml
density = 50 g = 1.67 g
30 ml
ml