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/s 2.

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/s 2.  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 friction- friction 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