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 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