BYU Physical Science 100 Challenge Exam Review

Causality

Cause must always precede the effect.

Element

A substance made of atoms, all of which contain the same number of protons.

Position Symmetry

The laws of the universe are not different at different locations.

Authority

An accepted source of expert information or advice

Gravity

The force that arises from the interaction of anything with mass

Law

A well-tested theory, so firm as to be unquestioned by science

Existence

The assertion that a world separate and distinct from our minds that actually exists

Force

Any of the four fundamental ways in which elementary particles and bodies can influence each other.

Hypothesis

A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation

Reason

The capacity for logical, rational, and analytic thought; intelligence

Model

A schematic description of a system, theory, or phenomenon that accounts for its known or inferred properties and may be used for further study of its characteristics

Strong Nuclear Interaction

The interaction between nucleons that holds them together

Time Symmetry

The laws of the universe do not change with time.

Sensory Data

Knowledge obtained through seeing, hearing, touching, tasting, and smelling

T/F: Protons and neutrons together form atomic nuclei.

True

T/F: Occam's razor states that complex explanations are more likely to be true than simple explanations.

False

T/F: Intuition is the act or faculty of knowing or sensing outside the five physical senses.

True

T/F: A physical law, such as Newton's First Law of Motion, can never be proved wrong.

False

T/F: The physical laws on Mars are slightly different than the laws on Earth due to the differences in each planet's composition.

False

A boat glides through the water on a lake at constant speed in a straight line.

Newton's First Law

An airplane circles the airport at a constant speed while waiting to land.

Newton's Second Law

A marathon runner begins running faster just before crossing the finish line.

Newton's Second Law

Comparing the sizes of all forces that arise when a book sits on a table.

Newton's Third Law

Describing the motion of a bench in the park.

Newton's First Law

An accelerating bullet causing the recoil of a gun.

Newton's Third Law

A hot air balloon rising straight up at a constant speed.

Newton's First Law

A submarine falling straight towards the ocean bottom at a constant speed.

Newton's First Law

Comparing the forces on two boxers' gloves as they come in contact.

Newton's Third Law

Newton's First Law (Law of Inertia)

An object in motion (or at rest) will tend to stay in motion (or at rest) until it is acted upon by an outside force.

Newton's Second Law

F=MA (force = mass x acceleration)

Newton's Third Law

For every action force there is an equal and opposite reaction force

T/F: The laws of nature are treated differently for an object in uniform motion and an object at rest.

False

T/F: If an object changes its state of motion (i.e. its direction or speed) then it must be accelerating.

True

T/F: When an astronaut travels to the moon, his or her weight changes. Therefore, the astronaut's mass must also change.

False

T/F: For an object to change its state of motion, an unbalanced force must act on it.

True

T/F: Objects that interact always exert the same strength of force on one another.

True

When a body is acted upon by a single constant unbalanced force,

it will experience a constant acceleration in the direction of the force.

If an object is moving in a straight line at a constant speed, what must be true?

The total force on the object is zero.

Weight

The gravitational force the earth exerts on an object.

Newton's Law of Gravity

F=GMm/r^2

T/F: A small ball is dropped from the edge of a cliff. One-tenth of a second later a much heavier ball is dropped from the same position. Ignoring the effects of air friction, the second ball will accelerate faster and overtake the first.

False

T/F: Although the moon is so far away, its gravitational pull still affects Earth.

True

T/F: The force of gravity increases between objects as they get farther away from each other.

False

T/F: Because the Moon orbits Earth at a constant speed, it travels in uniform motion.

False

T/F: A cannon ball weighs a lot more than a marble. This means it requires much more force to "fall" towards Earth at the same rate as a marble.

True

If a feather and a brick are dropped at the same height in a vacuum, then

they hit the ground at the same time

A rock is dropped from a cliff. When is the force of gravity greatest on the rock?

the force of gravity is constant throughout the entire flight of the rock

Jane throws a rock horizontally off a cliff. How fast is the rock traveling downward after 5 seconds (ignore air friction, use 10 m/s2 for g)?

50 m/s

Using the Principle of Position Symmetry, the gravitational force on an object near another planet would

depend on the masses of the planet and the object and the square of the distance between them.

A baseball player throws a baseball horizontally at 100 mph. You drop a penny at the exact same height just as the ball leaves the baseball player's hand. Air friction is negligible. Which of the following is true?

The baseball has a greater force on it than the penny.

The Electric Force Law

The mathematical formula F = kqQ/d2 which describes the strength of the force between two objects of charge Q and q with their centers separated by the distance d.

Proton

The basic positive charge-carrying particle in an atom.

Ferromagnetic

Metal alloys that are attracted to magnets or are capable of being transformed into a permanent magnet.

Insulator

A material that does not permit electrons to flow through it.

Alternating Current

A current of electrons that changes direction of flow.

The unit of measure for charge.

Coulomb

Conductor

material that allows electrons to flow through it easily (ex. metals)

Electron

The basic negative charge-carrying particle in an atom.

Direct current

A steady flow of electrons in one direction through a wire

Contact force

A repulsive force between electrons near the surface of two different objects.

Electric force constant

A number relating the strength of the electric force to the charges involved and their distance apart.

neutron

A neutral particle found in the nuclei of atoms.

T/F: Friction comes from electromagnetic forces.

True

T/F: Electric force becomes stronger if the charged objects are moved farther apart.

False

T/F: Neutrons have a negative charge

False

T/F: Iron and nickel are examples of ferromagnetic metals.

True

T/F: Electric currents exert forces on permanent magnets.

True

Suppose you wanted to exactly double the electric force between two objects. How could you accomplish that?

Double the charge on one of the objects.

T/F: If an object is at rest, no forces are acting on it.

False

Pressure

The force on an object divided by the area over which the force is applied.

Convection

Circulation in a fluid caused by termperature and density differences.

Unbounded fluids

Fluids pulled toward Earth and held in place by the force of gravity.

Buoyant force

Equals the weight of the displaced fluid.

Fluid

Anything that Flows

Bounded fluids

Type of fluid where pressure acts with equal force on all areas of the confining walls

T/F: Air is considered a fluid.

True

T/F: If an object is floating, the buoyant force on it is larger than its weight.

False

T/F: Objects that float in air, such as helium ballons, are weightless.

False

inertial frame of reference

An object or location that is experiencing no acceleration

non-inertial frame of reference

An object or location that is undergoing an acceleration

motion symmetry

The observation that the laws of nature are the same for all inertial frames of reference

General Theory of Relativity

The theory that considers non-inertial frames of reference

Galilean Relativity

The notion that separate speed vectors can be added together in a "straight-forward" way to form a total velocity vector

Relativity

The idea that motion is only defined relative to other objects, which may have their own motion

Special Theory of Relativity

The theory that describes how nature behaves when encountering high speeds

Gedanken Experiment

The theory that describes how nature behaves when encountering high speeds

conserved quantity

Any quantity that remains constant.

carbon cycle

The process by which carbon is transferred through the atmosphere to living organisms and back to the atmosphere.

atomic mass number

Obtained by adding the number of protons to the number of neutrons.

linear momentum

An object's mass times its velocity.

angular momentum

An object's mass times its speed times its distance from the center of its orbit.

fundamental particles

Small, unbreakable constituents of matter.

potential energy

Depends on an object's position.

internal energy

Depends on the position and motion of the object on the atomic scale.

gravitational potential energy

Weight times height.

mechanical energy

Depends on the position and motion of the whole object.

work

Moving an object in the direction of an applied force.

perpetual motion machine

Something that keeps moving forever without any energy being added

kinetic energy

Depends on an object's motion.

conduction

Energy transferred through direct contact.