Phys Science Final

What does a magnet attract?

Iron objects.

What exerts a force on magnetic materials and other magnets?

A magnetic field.

Where is the magnetic force strongest on a magnet?

At both poles.

What are groups of atoms with aligned magnetic poles called?

Magnetic domains.

What happens to an object when its magnetic poles are aligned?

It becomes magnetized.

How can a magnetic field be represented?

By lines of force called magnetic field lines.

What are the two types of poles on a magnet?

North pole and south pole.

What occurs when two north poles or two south poles are brought together?

They repel each other.

What occurs when a north pole and a south pole are brought together?

They attract each other.

What is an electromagnet?

A temporary magnet made by wrapping a wire around an iron core.

How does the strength of the magnetic field change with current in a wire?

As the current increases, the strength of the magnetic field increases.

What device changes electrical energy into mechanical energy?

An electric motor.

What is electromagnetic induction?

The generation of a current by a changing magnetic field.

What is produced by moving a loop of wire through a magnetic field?

An electric current.

What is formed when a solenoid is wrapped around an iron core?

An electromagnet.

How much stronger can the magnetic field inside a solenoid with an iron core be compared to one without?

More than 1,000 times stronger.

What is the function of a generator?

To change mechanical energy to electrical energy.

What does a galvanometer measure?

Electric current.

How does a transformer change electric voltage?

By increasing or decreasing voltage.

What is a step-up transformer?

A transformer that increases voltage.

What is a step-down transformer?

A transformer that decreases voltage.

Why is alternating current transmitted at high voltage?

To minimize energy loss as heat.

What is conservation in the context of energy resources?

The wise and careful use of energy resources.

What type of fossil fuel is coal?

The most abundant fossil fuel formed from the remains of plants.

What is petroleum?

A flammable liquid formed by decayed organisms.

What process separates different compounds found in petroleum?

Fractional distillation.

What are unwanted radioactive products from nuclear reactions called?

Nuclear wastes.

What is hydroelectric energy?

Electricity produced by falling water.

What is tidal energy?

Energy from water that flows due to gravitational forces among Earth, the Moon, and the Sun.

What is carrying capacity?

The largest number of individuals of a particular species that the environment can support.

What is a common efficiency percentage for most power plants?

Approximately 35%.

What is the core of a nuclear reactor?

The part where the fuel is located.

How is electricity produced in a nuclear reactor?

From controlled fission chain reactions.

What is the role of control rods in a nuclear fission reactor?

To slow down neutrons and control the reaction.

What are hazardous wastes?

Wastes that are poisonous, cause cancer, or can catch fire.

Why are alternative energy sources needed?

Because the supply of fossil fuels is diminishing.

What is magnetism?

The properties and interaction of magnets.

How can electric current be measured?

Using a galvanometer.

What is a turbine?

A large wheel that rotates when pushed by water, wind, or steam.

What is geothermal energy?

The thermal energy contained in hot magma.

How do natural resource consumption rates in the U.S. compare to other countries?

More natural resources are used per capita than in most countries.

What are photovoltaic cells?

Devices that use semiconductors to produce electricity from solar energy.

What does a photovoltaic cell convert?

Electromagnetic energy into electrical energy.

What are the four characteristics of waves?

Amplitude, wavelength, speed, and frequency.

What is a wave?

A disturbance that transfers energy through matter or space.

How does a transverse wave move?

At a 90° angle to the energy that created it.

How does a longitudinal wave move?

In the same direction as the energy that created it.

What happens to a wave when it hits a surface?

It reflects.

What is the unit for wavelength?

Meter.

What is the unit for frequency?

Hertz (Hz).

What is the formula for wave speed?

Speed = wavelength X frequency.

What is resonance?

Vibration of a material at its natural frequency.

What occurs during constructive interference?

Two waves overlap and their crests (troughs) add together to form a larger wave.

What occurs during destructive interference?

Two waves overlap and their crests (troughs) subtract to cancel or form a smaller wave.

What determines how fast sound travels?

The type of medium, density, elasticity, and temperature of the medium.

What is the unit for loudness (intensity)?

Decibels (dB).

What are the three ways light can interact with materials?

Transmitted, reflected, or absorbed.

What is the difference between opaque, translucent, and transparent materials?

Opaque materials absorb or reflect light; translucent materials transmit some light but scatter it; transparent materials transmit light without scattering.

What are the primary pigment colors?

Magenta, cyan, yellow.

What are the primary light colors?

Red, blue, green.

What is the result of mixing all primary pigments?

Black.

What is the result of mixing all primary light colors?

White.

What type of reflection occurs when light reflects off a mirror?

Normal reflection.

How do you see your reflection in a mirror?

Light reflects off you, then from you to the mirror, and back to your eye.

What are the advantages of fluorescent light bulbs over incandescent bulbs?

They last longer, are less expensive, produce less heat, and use less energy.

What happens to light waves when they pass from one medium to another?

They are refracted.

What causes regular reflection?

Smooth materials like glass and calm water.

What causes diffuse reflection?

Rough surfaces like brick, fabric, and leather.

Why do objects have color in white light?

They reflect specific color wavelengths from their surface.

What happens to a blue object viewed through a red filter?

It appears black.

What happens to white light passing through a red filter?

All of the red light is transmitted.

What is the filament in an incandescent light bulb usually made of?

Tungsten.

How does an incandescent bulb produce light?

Electrons flow through the filament, causing it to heat up and glow.

What are the characteristics of incandescent light bulbs?

They are inefficient, use a lot of energy, and don't last long.

What gas is typically used in sodium vapor lights?

Argon.

What type of light does a Neon light produce?

Colored lights using noble gases.

What is coherent light?

Light directed in one direction, produced by lasers.

What are the three sections of the ear?

Auricle (outer ear), tympanic membrane (eardrum), cochlea.

What is the function of the auricle?

It collects sound and funnels it to the eardrum.

What is the amplitude of a sound wave dependent on?

How tightly packed the sound molecules are.

What is pressure defined as?

A force exerted over a given area.

What is the SI unit of pressure?

Pascal (N/m²).

What is buoyancy?

The ability to float, caused by upward pressure from a fluid.

What does Archimedes' principle state?

The weight of the fluid displaced by an object is equal to the buoyancy force acting on that object.

What is the density of water?

1 g/cm³.

What does Bernoulli's Principle state about fluid speed and pressure?

As fluid speed decreases, pressure increases; as speed increases, pressure decreases.

How does elevation affect pressure on your body?

Pressure is less at higher elevations and greater at lower elevations.

What is thrust in the context of airplanes?

The forward force applied to an object, created by propellers.

How do propeller blades create thrust?

They create a pressure differential when they spin.

What creates thrust in an airplane?

The pressure difference between the lower pressure in front of the propeller and the higher pressure behind it.

What shape is an airplane wing designed to create lift?

An airfoil shape.

According to Bernoulli's Principle, what happens to pressure as a fluid increases in speed?

The pressure decreases.

What two forces must an airplane overcome to leave the ground?

Gravity and Drag.

Why does a helium-filled balloon float while a breath-filled balloon sinks?

Helium is less dense than air, while the breath-filled balloon is denser due to compressed air.

What balances the weight of the air pushing down on your body?

The fluids in your body exert an outward force equal to the force of the air.

What does Pascal's Principle state?

When a force is applied to a fluid in a contained space, the pressure is transmitted equally throughout the fluid.

What are the three types of chemical bonds?

Ionic, Covalent, and Metallic.

What is an atom considered stable?

When it has 8 valence electrons.

What is the maximum number of electrons that can occupy the first two energy levels of an atom?

The first energy level holds 2 electrons, and the second holds 8 electrons.

What is an ion?

An atom that has gained or lost an electron.