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 g/cm3

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 v=lxwxhd=5g/40cm3 V=40 cm3

d=0.125 g/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