Physical Science Test Out

How do greenhouse gases warm Earth?

They trap infrared radiation and re-radiate heat back toward the surface

What are sources and sinks of carbon dioxide?

Sources: burning fossil fuels, respiration. Sinks: oceans, forests

Name the stages of star life

The stages of star life are: Nebula, Protostar, Main Sequence, Red Giant or Supergiant, White Dwarf/Neutron Star/Black Hole

How is evidence about star life gathered?

Evidence is gathered using telescopes, spectroscopy, and studying light and energy emitted by stars

Compare our Sun to other stars in terms of size and stages

It is a medium-sized star; it will go through the main sequence, red giant, and white dwarf stages

Which elements are fused in different star stages?

Hydrogen fuses into helium during the main sequence; heavier elements like carbon and oxygen fuse in later stages

What is the H-R Diagram?

A plot of stars showing the relationship between their brightness and temperature

Where were all the elements on Earth formed?

Most elements were formed inside stars through nuclear fusion and supernova explosions

How is energy produced in a star?

Energy is produced by nuclear fusion, primarily hydrogen atoms fusing into helium

Explain the balance between fusion and gravity in a star

Fusion creates outward pressure balancing the inward pull of gravity, maintaining star stability

What evidence supports that the universe is expanding?

Redshift of galaxies shows they are moving away from us, indicating expansion

What evidence supports the Big Bang Theory?

Background cosmic microwave radiation and redshift of galaxies support the Big Bang

What happens when solar radiation interacts with Earth's surface and atmosphere?

Solar radiation is absorbed, reflected, or transmitted by Earth's surface and atmosphere

How do greenhouse gases cause Earth's temperature to warm?

They trap heat by absorbing and re-emitting infrared radiation, warming the atmosphere

What happens to atmospheric carbon dioxide levels over Earth's history?

Levels have fluctuated naturally but increased sharply due to human activity recently

How does carbon dioxide travel through Earth's system?

CO2 cycles through the atmosphere, oceans, plants, and soil as sources and sinks

How does temperature affect the ocean's ability to absorb carbon dioxide?

Warmer oceans absorb less CO2, affecting carbon cycle balance

What role does water vapor play in Earth's temperature?

Water vapor is a greenhouse gas that amplifies warming through positive feedback

What is the positive feedback loop between temperature and ice cover?

Higher temperatures melt ice, reducing reflectivity and increasing absorption of heat, further warming

What is the negative feedback loop between cloud cover and temperature?

More clouds can reflect sunlight, cooling Earth and reducing temperature

Why is it necessary to consider multiple factors when modeling climate?

Because interactions between gases, temperature, water vapor, and clouds are complex and uncertain

Why do light-colored surfaces have a cooling effect on Earth?

They reflect more sunlight, reducing heat absorption and cooling the surface

What is renewable energy?

Energy from sources that are naturally replenished, like solar and wind

What is nonrenewable energy?

Energy from sources that can be depleted, like coal and oil

Name three renewable energy sources.

Solar, wind, and hydroelectric

Why is energy conservation important?

It reduces demand, saves resources, and lowers environmental impact

What is a cost benefit ratio of natural resource consumption?

A comparison of the environmental, economic, and social costs versus benefits

How do humans impact the environment?

Through resource use, pollution, habitat destruction, and climate change

What are consequences of human impact on the environment?

Loss of biodiversity, climate change, pollution, and resource depletion

What is sustainability?

Meeting current needs without compromising future generations' ability to meet theirs

What strategies help reduce human impact on natural systems?

Using renewable energy, recycling, conservation, and sustainable practices

Why must natural resource management be careful?

To balance human needs with ecosystem health and resource availability

What are the main layers of the Earth?

Crust, mantle, outer core, inner core

Where is the Earth's magnetic field generated?

In the outer core by movement of molten iron

How do scientists infer Earth's interior layers?

By analyzing patterns of seismic P and S wave arrivals

What is magnetic dip of a rock?

The angle between Earth's magnetic field and the rock's magnetic direction

What evidence did magnetic dip provide in India?

It showed past movement of tectonic plates

What is the theory of Pangaea?

That all continents were once joined in a single supercontinent

What is an earthquake epicenter?

The point on Earth's surface directly above the earthquake focus

What is an earthquake focus?

The actual location underground where the earthquake starts

Where are major earthquake zones located?

Along tectonic plate boundaries and fault lines

How do earthquakes provide evidence for plate tectonics?

They occur at plate boundaries showing plate movement

What is the difference between oceanic and continental crust?

Oceanic is thin and dense; continental is thick and less dense

What causes tectonic plates to move?

Heat-driven mantle convection and cooling, sinking ocean plates

Name the four types of plate boundaries.

Divergent, convergent, transform, and plate boundary zones

What happens at divergent boundaries?

Plates move apart, new crust is formed

What happens at convergent boundaries?

Plates move together, crust is destroyed or uplifted

What happens at transform boundaries?

Plates slide past each other causing earthquakes

Name three major types of volcanoes.

Shield volcano, stratovolcano, cinder cone

How are shield volcanoes formed?

From low-viscosity lava flows creating wide, gently sloping sides

What are hotspots?

Areas where magma rises from deep in the mantle, like Hawaii

What is frequency of a wave?

Number of wave cycles per second (Hz)

What is wavelength?

Distance between successive crests or troughs of a wave

What is wave energy related to?

Frequency and amplitude of the wave

Name the categories of the electromagnetic spectrum.

Radio, microwave, infrared, visible, ultraviolet, X-ray, gamma ray

What is reflection of a wave?

Bouncing of a wave off a surface

What is absorption of a wave?

When wave energy is taken in by a material

What is transmission of a wave?

Wave passing through a material

What is scattering of a wave?

Wave spreading out after hitting particles

Why can radio waves travel through space but sound waves cannot?

Radio waves are electromagnetic and don't need a medium; sound waves need a medium

Why do we see lightning before hearing thunder?

Light travels faster than sound

What is the wave speed formula?

v = frequency (ƒ) × wavelength (λ)

What are the parts of a transverse wave?

Crest, trough, wavelength, amplitude

What are the parts of a longitudinal wave?

Compression, rarefaction, wavelength

What is wave interference?

When two waves meet and combine

What is the difference between analog and digital signals?

Analog is continuous; digital is discrete steps

Name one advantage of digital signals.

Less noise and distortion during transmission

Name one disadvantage of analog signals.

More susceptible to noise and signal loss

What is displacement?

The straight-line distance and direction from the starting point to the ending point

How do you calculate speed?

Speed = distance ÷ time

What is velocity?

Speed with a specified direction

What is acceleration?

Rate of change of velocity over time

What does Newton's First Law state?

An object in motion stays in motion unless acted on by an unbalanced force

What does Newton's Second Law state?

Force equals mass times acceleration (F = ma)

What is the difference between mass and weight?

Mass is amount of matter; weight is force of gravity on an object

What is net force?

The overall force acting on an object after all forces are combined

What is friction?

A force that opposes motion between two surfaces in contact

What is terminal velocity?

The constant speed an object reaches when the force of gravity is balanced by air resistance

What is momentum?

Mass multiplied by velocity

What is conservation of momentum?

Total momentum in a closed system remains constant

What is an elastic collision?

A collision where kinetic energy is conserved

What is an inelastic collision?

A collision where kinetic energy is not conserved

What is impulse?

Change in momentum caused by a force over time

How can impulse be limited in real-world situations?

By increasing the time over which the force is applied (e.g., airbags)

What are different types of energy?

Kinetic, potential, thermal, chemical, electrical, nuclear, and more

Give an example of energy transformation.

A battery converting chemical energy to electrical energy to power a device

What is gravitational potential energy?

Potential energy stored due to an object's height above the ground

What is the formula for gravitational potential energy?

PE = mgh (mass × gravity × height)

What is kinetic energy?

Energy of motion

What is the formula for kinetic energy?

KE = 1/2 mv² (one-half mass times velocity squared)

What does the Law of Conservation of Energy state?

Energy cannot be created or destroyed, only transformed

What is electric current?

The flow of electric charge, measured in amperes (A)

What is voltage?

The electric potential difference between two points, measured in volts (V)

What is resistance?

A measure of how much a material opposes the flow of current, measured in ohms (Ω)

What is power in an electric circuit?

The rate at which electrical energy is transferred, measured in watts (W)

Describe the flow of current in an open circuit.

No current flows because the circuit is broken

Describe the flow of current in a closed circuit.

Current flows continuously through the circuit

Describe a series circuit.

Components are connected end-to-end so current flows through each component sequentially

Describe a parallel circuit.

Components are connected across common points, providing multiple paths for current

How do you calculate total voltage in a series circuit?

Add the voltages across each component