Transcript Chapter 3 Review - St. Paul School

Chapter 3
Review
Vocabulary
 When the upward and downward
forces on a falling object are
equal, the object reaches
_____________.
 Terminal Velocity
Vocabulary
 The force that holds the particle
sin the nucleus together is the
__________.
 Strong Nuclear Force
Vocabulary
 The SI unit for force is _______.
 Newton (N)
Vocabulary
 A push or pull that starts or stops
the motion of an object or
changes its direction is called
a(n) __________.
 Force
Vocabulary
 Gravitation, electromagnetic, and
strong and weak nuclear forces
are _________.
 Universal Forces
Vocabulary
 When you body is at rest, you
have __________.
 Inertia
Vocabulary
 The force that opposes motion is
__________.
 Friction
What Doesn’t Belong?
 Universal Force, Electromagnetic
Force, Gravitational Force.
 Universal Force- this is the
general term that includes
electromagnetic and gravitational
forces.
What Doesn’t Belong?
 Sliding, Rolling, Momentum
 Momentum- Sliding and rolling
are types of friction; momentum
is a property of a moving object.
What Doesn’t Belong?
 Electrical, Magnetic, Centripetal
 Centripetal Force- Electric and
magnetic are forces between
objects; centripetal force is the
force required to make an object
move in a circle.
What Doesn’t Belong?
 Terminal Velocity, Constant
Acceleration, Friction
 Constant Acceleration- Terminal
velocity is reached because of
friction between the object and
the air.
What Doesn’t Belong?
 Weak Force, Strong Force,
Sliding Force
 Sliding Force- the sliding force is
not one of the universal forces.
Check Your Knowledge
 What causes a ball to follow a
curved path when you throw it?
 A thrown ball follows a curved
path because of the force of
gravity on the ball.
Check Your Knowledge
 What is terminal velocity?
 Velocity at which the force of
gravity pulling down on a falling
object is exactly balanced by the
force of air resistance pushing
upward, resulting in that object
falling at a constant velocity.
Check Your Knowledge
 How is gravity related to the
weight of an object?
 The weight of an object is a
result of the force of gravity on
the object.
Check Your Knowledge
 List three different kinds of force
you use when you ride your bike.
 Force of your muscles on the
pedals and handlebars; force of
your weight on the seat; force of
friction from the pavement
pushing on the tires; force of
gravity on the bike.
Check Your Knowledge
 Calculate the acceleration of a
70-kg mass on a swing if you
push it with a 40-N force.
 a=F/m; a= 40N/70kg; a=
0.57m/s2.
Check Your Knowledge
 How does the force of gravity
form the moon affect the Earth?
 The force of gravity from the
moon causes tides on Earth.
Check Your Knowledge
 What is centripetal force?
 Centripetal force- a force that
causes an object to move in a
circular path.
True or False?
 The force that holds the nucleus
together is the strong nuclear
force?
 True
True or False?
 Momentum can transfer from one
object to another object.
 True
True or False?
 The acceleration of the Earth’s
gravity is 9.8m/s2.
 True
True or False?
 According to Newton’s second
law, acceleration decreases as
mass increases.
 True
True or False?
 According to the second law of
motion, force is equal to mass
times speed.
 False; acceleration
True of False?
 The electric force and the
magnetic force are both a result
of charge particles.
 True
True or False?
 Newton’s third law of motion
could be called the law of inertia.
 False; first
Check Your Understanding
 An object’s velocity times its
mass is _______.
 Momentum
Check Your Understanding
 What are the three types of
friction and when do they occur?
 Fluid friction- when moving
through air or liquid. Rolling
friction- friction that occurs
between a rolling object and
another surface. Sliding frictionfriction that occurs between two
objects that are sliding past one
another.
Check Your Understanding
 Rank the strength of the
universal forces from weakest to
strongest.
 1. Gravitational 2. Weak Nuclear
3. Electromagnetic 4. Strong
Nuclear
Check Your Understanding
 Which kinds of forces attract?
Which kind repel?
 Like forces repel and opposite
forces attract.
Check Your Understanding
 What do nuclear forces act on?
What makes one weak and the
other strong?
 Nuclear forces act on the nucleus
of atoms (protons and neutrons).
Strong nuclear forces keep the
nucleus together; Weak Nuclear
forces cause nuclear decay.
Check Your Understanding
 Which object will accelerate
faster when the same amount of
force is applied to them, a cart
that weighs 20kg or a cart that
weighs 40 kg?
 The 20kg cart.
Check Your Understanding
 Is the force needed to overcome
sliding friction greater than or
less than the force needed to
overcome rolling friction?
 Greater than
Check Your Understanding
 If you were to travel to a planet
that has less gravity than earth,
would you weigh: the same as,
less than, or greater than you do
on earth?
 Less than