Chapter 3 Review
•Study Guide
•Vocab Challenge
1) DEFINE:
• Mass: The amount of matter in an object
• Weight: The gravitational force exerted on an object.
• Volume: The amount of space taken up by an object.
• Density: Mass per unit volume
• Buoyant force: An upward force on an object in a fluid exerted
by another fluid.
• Density:
Which one is more dense?
2) A SOLID RUBBER STOPPER HAS A MASS OF
33.0 GRAMS AND A VOLUME OF 30.0 CM3.
WHAT IS THE DENSITY OF RUBBER?
d=m/v
d= 33.0 g/30.0 cm3
d= 1.1
3
g/cm
3) A LARGER SOLID RUBBER STOPPER HAS A MASS OF
49.5 GRAMS AND A VOLUME OF 45.0 CM3. CALCULATE
THE DENSITY. DID IT CHANGE? WHY?
• The density is still 1.1 g/cm3
Why??
• Density does not change with the size of the sample.
• As long as you are measuring the same substance, the density
will always be the same.
4) IF THE MASS OF AN OBJECT IS 5G AND IT IS
2CM WIDE, 10 CM TALL, AND 2CM LONG, WHAT
IS ITS DENSITY?
d=m/v
d=5g/40cm3
d=0.125 g/cm3
v=lxwxh
V=40 cm3
5) WHAT ARE THE UNITS USED FOR DENSITY?
• 1 g/cm3 = 1 g/mL
• 1000 kg/m3 = 1000 kg/L
6) LIST THE STEPS NEEDED TO FIND THE VOLUME OF
A TOY CAR.
1) Record volume of water
2) Place object in water and record combined volume.
3) Subtract the starting volume from the ending volume to
find out how much water was displaced.
4) The amount of displaced water is the volume of the toy
car.
7) DO BUOYANT FORCES REFER TO THE WEIGHT OF
AN OBJECT OR THE MASS OF AN OBJECT? EXPLAIN
• The weight, because buoyant forces are
affected by gravity and weight is the
gravitational force on a object.
• Since weight and gravity are closely related,
and the only vertical forces at work are
buoyancy and gravity, weight is what matters.
8) WHY DO BOATS FLOAT? REFLECT ON YOUR BOAT
LAB.
• Boats can float only if their volume is increased
enough to displace a greater amount of water than
it would if it were crumpled in a ball.
9) EXPLAIN ARCHIMEDES’ PRINCIPLE IN YOUR OWN
WORDS.
• The buoyant force on an object is equal
to the weight of the fluid the object
displaces.
• Pulling cards…
10) WHY IS ARCHIMEDES’ PRINCIPLE USEFUL?
• You tell me!
• (Pulling cards…)
• Just to name a few:
• Helps us find volume of things we don’t have a
formula for.
• Helps us understand how fish, submarines, and
scuba divers can control their depth.
• Helps us understand how boats float.
DO WE HAVE TIME FOR A…
Vocab challenge?
The gravitational force exerted on an
object. It is a force that points toward
the center of Earth.
Weight
Mass per unit volume (g/cm3)
Density
Use to measure a liquid's volume.
Graduated Cylinder
Amount of matter in an object.
Does not change with location.
Mass
An upward force on an object in
a fluid exerted by another fluid.
Buoyant Force
The buoyant force on an object is
equal to the weight of the fluid the
object displaces.
Archimedes’ Principle
Is the curve in the upper surface of a
liquid close to the surface of the
container, caused by surface tension.
Meniscus
The amount of space taken up by an object.
Volume