Physics Ch. 5 & 6

Which of the following is true about waves?

I.   Waves transfer only energy, not matter.

II.  Waves can travel through vacuum.

III. Sound waves are generated by vibrational disturbances.

IV. Radio waves can propagate without a medium.

I, II, III, and IV

The classification of waves into transverse or longitudinal is based on particle motion and wave___________

direction

The propagation of a longitudinal wave creates alternating regions of high pressure or compression and low pressure or_____________.

rarefaction

The Greek letter, lambda, is the universal symbol for the _____________ of a wave.

wavelength

The _____________ is the number of oscillations or cycles per unit of time.

frequency

The equation that relates period and frequency is

T = 1/f

A frequency of 5 Hz means that…

5 wavelengths would pass by an arbitrary point per second.

____________ waves consist of oscillating electric and magnetic fields.

electromagnetic

In between the infrared (IR) region and the ultraviolet (UV) region is a small portion of the electromagnetic spectrum called the _____________, which is detectable by the human eye. 

visible

Which one is the correct numerical solution for calculating the wavelength, in meters, of a 90.0 MHz radio wave assigned to an FM station?

(3.00 x 10⁸ m/s)  /  (90 x 10⁶/s)

The ____________ region of the sound spectrum represents the frequency perceptible by the human sense of hearing. 

audible

The loudness of sound is associated with _______________, the rate of sound energy transfer through a given area.

intensity

A tuning fork is moved 2.5 times farther away from its original distance with respect to a sensitive recorder. The intensity of the sound from the relocated tuning fork is expected to 

decrease to 0.16 times the original intensity.

_____________ is the perceived highness or lowness of sound.

pitch

Sound intensity level is expressed in units of?

decibles or dB

The permissible noise exposure to a rock band that continuously generates a sound intensity level of 110 dB is _________ minutes.

30

Doppler effect is the _________ change in the frequency of sound from a moving source or observer.

apparent

A motorboat traveling faster than the wave speed in water creates a V-shaped _______ wave.

bow

A jet pilot flying faster than the speed of sound cannot hear any sound.

False

At the node of a standing wave, the displacement of the superimposed waves is zero.

True

_________ is energy in transit.

heat

Which of the following statements is true about the Kelvin temperature scale?

I. The zero in the Kelvin scale is referred to as the absolute zero.

II. The change in temperature in the Kelvin scale is equal to the change in temperature in the Celsius scale.

III. The unit of temperature in the Kelvin scale is oK.

I and II

at what value is the temperature in the Celsius scale equal to that in the Fahrenheit scale?

-40

The normal healthy human body temperature ranges from:

96 F to 101 F

at the molecular level, which of the following does not contribute to the kinetic energy?

intermolecular forces of attraction 

one food calorie (Cal) is equivalent to_____.

1 kcal

at what temperature does liquid water begin to expand upon cooling?

4 °C

equal masses of iron, mercury, wood, and ethyl alcohol were subjected to 10 kJ of heat. which substance would show the smallest change in temperature?

ethyl alcohol

heat capacity is sometimes described as thermal__________.

inertia 

which of the following phase changes requires the most amount of heat?

evaporation of 1kg of liquid water

which of the following changes involves the release of energy (“energy out”) to the surroundings?

freezing

when liquid evaporates, work must be done to break ______________________ and separate the molecules.

intermolecular bonds

the boiling point of water at ordinary room conditions is 100 C. how can one increase the boiling point of water?

increase the pressure above the liquid water.

which of the following “kitchen relations” is/are true at different pressures?

I.water boils at a temperature lower than 100 C at high altitudes.

II. a sealed pressure cooker creates high pressure that decreases the boiling point of water.

III. cake mixes pre-made for high altitude would rise slower when used at sea level

I and III.

the bottom of many cooking pans is commonly made of copper, whereas the handle is coated with plastic. the design is based on the fact that….

copper is an excellent thermal conductor whereas most plastics are insulating.

which of the following identical cylinders, of equal masses and temperatures, would feel coldest when placed on the palm of your hand?

iron

_________solids such as asphalt and glass do not have definite melting points and gradually soften upon heating.

amorphous

N/m² is the SI unit for __________

pressure

the charged particle carrying hot gas inside a fluorescent lamp is a common phase of matter called _____________.

plasma

during the Heimlich maneuver, an inward-upward thrust below the diaphragm compresses the lungs, thereby forcing air out of the lungs to dislodge any obstruction in the trachea. this series of actions demonstrates that ___________.

pressure is inversely proportional to volume at constant temperature and number of particles

for a given gas, pressure is directly proportional to the:

I. inverse of volume 1/V

II. temperature T in Kelvin

III. number of particles

I, II, and III.

what is the algebraic convention used by the textbook in describing the heat and work transactions according to the first law of thermodynamics?

H is + when heat is absorbed by the system. W is + when work is performed by the system.

the second law of thermodynamics expresses the impossibility of completely converting heat H, into useful work, W.

true

thermal equilibrium is achieved when

two objects, initially at two different temperatures, would have the same temperature after contact.

Which temperature scale has the smallest degree interval?

Fahrenheit

which of the following phrases best describes heat?

energy in transit because of a temperature difference.

the term sublimation refers to which of the following phase changes?

solid to gas

which of the following methods of heat transfer generally involves mass movement?

convection

the heat we get from the Sun is transferred through space by which process?

radiation

which of the following has a definite volume but no definite shape?

liquid

pressure is defined as:

force divided by area

when we use the ideal gas law, the temperature must be in which unit?

K

when heat is added to a system, it goes into which of the following?

doing work and/or increasing the internal energy

the direction of a natural process is indicated by which of the following?

change in entropy

If a piece of ribbon were tied to a stretched string carrying a transverse wave, how would the ribbon be observed to oscillate?

perpendicular to wave direction

how fast to electromagnetic waves travel in vacuum?

3.00 x 10⁸ m/s

Which one of the following regions has frequencies just slightly less than the visible region in the electromagnetic frequency spectrum?

infrared

Sound waves propagate in which of the following?

solids, liquids, and gas 

What is the lower frequency limit of the audible range of human hearing?

20 Hz

A sound with an intensity level of 30 dB is how many times louder than the threshold of hearing?

1000

A moving observer approaches a stationary sound source. What does the observer hear?

an increase in frequency

Which of the following properties does not change in the Doppler effect?

speed

If an astronomical light source were moving toward us, what would be observed?

a blueshift

Longitudinal wave: particle displacement is ___________________ to wave velocity.

parallel

Transverse wave: particle displacement is ______________to wave velocity.

perpendicular

Example of a longitudinal wave:

sound wave in air

Example of transverse wave:

light wave

Which end (blue or red) of the visible spectrum has the longer wavelength? Which has the lower frequency?

The red end.

How far does light travel in one year? [This distance is known as a light-year (ly) and is used in measuring astronomical distances.]

9,460,000,000,000 km

what is thermodynamics?

science of how thermal energy and other energy forms (like mechanical energy) are converted between different forms, described by macroscopic properties.

Energy cannot be created or destroyed. It states that the change in internal energy (ΔE) of a system is the sum of heat (H) exchanged with the surroundings and work (W) done by/on the system (ΔE = H - W).

first law of thermodynamics

Heat spontaneously flows from hotter to colder objects. It also introduces entropy (S), a measure of energy dispersal. In isolated systems, entropy never decreases, tending towards greater disorder. It determines which processes allowed by the First Law are spontaneous.

second law of thermodynamics

measure of energy dispersal or disorder in a system

entropy

At absolute zero (0 K), the entropy of a perfect crystalline solid is zero because particles are uniformly arranged and have zero kinetic energy. It allows for calculation of absolute entropy.

third law of thermodynamics

The amount of heat needed to raise the temperature of 1 kg of material by one degree Celsius. Often called "thermal inertia." Units: kcal/(kg·°C) or J/(g·°C).

specific heat ( c )

How does specific heat relate to temperature change for equal heat and mass?

Specific heat (c) and temperature change (ΔT) have an inverse relationship. A substance with a lower specific heat will experience a larger temperature change for the same amount of heat added and mass.

Alters intermolecular forces (e.g., evaporation, melting) but not chemical identity. Example: water evaporating to steam (still H₂O).

physical change

Breaks chemical bonds, altering the chemical composition. Example: intense laser beam breaking H₂O into H₂ and O₂.

chemical change

What happens to temperature during a phase change?

The temperature of a substance remains constant even though heat is continuously added.

Why does temperature remain constant during a phase change?

The heat energy added is used to overcome or form intermolecular forces (e.g., breaking bonds during melting/boiling, forming bonds during freezing/condensing) rather than increasing the kinetic energy of the particles.

The energy absorbed or released during a phase change without a change in temperature.

latent heat

Why does a fan feel cool even if the air isn't?

It speeds up evaporation of sweat from the skin. Evaporation absorbs heat from the body, leading to a cooling sensation. The fan helps by moving away humid air (convection) and replacing it with drier air, allowing more sweat to evaporate.

The rate at which energy is produced or consumed. Power = Energy / Time. Units: J/s (Watts), kcal/s, kJ/h.

power

How is electrical energy typically calculated and its common unit?

Electrical Energy = Power × Time. Common unit is kilowatt-hour (kW·h).

Gases that obey the relationship: p \propto \frac{NT}{V} where:

• p = pressure

• N = number of particles

• T = temperature (in Kelvin)

• V = volume

ideal gas

Conditions under which real gases deviate from ideal gas behavior

When gas particles interact significantly. This occurs at low temperatures (where gases tend to liquefy) and high pressures (leading to inter-particle collisions).

in gas law calculations, temperature must always be in what?

Kelvin

The rate of sound energy transfer through a given area. It is inversely proportional to the square of the distance from the source.

sound intensity

what is the threshold of human hearing?

Approximately 10^-12 Watts per square meter (W/m²)

What is the logarithmic scale of sound intensity called?

The decibel scale.

What does 0 dB represent?

The threshold of human hearing (corresponding to sound intensity of 10^-12 W/m²).

A gas is inside a sealed cylinder.  How does the pressure change if the volume is tripled and the temperature in the Kelvin scale is doubled?  

Decreases by a factor of 2/3

You have a balloon filled with air in your car overnight.  The balloon has a volume V in the morning, when the temperature is a cold 5°C.  By mid-afternoon the temperature has tripled to 15°C.  Why doesn't the volume of the balloon triple as well?  

Because the temperature doesn't triple when expressed in Kelvin

In general, sound travels fastest in

solids

When people in a football stadium do "The Wave" - where successive groups of spectators stand up and raise their arms - is the wave they are doing longitudinal, transverse, both, or neither?

transverse

How does the speed of a sound wave with a frequency of 400 Hz compare to the speed of a wave with a frequency of 800 Hz?

They both travel at the same speed

not a substance or fluid, it is a process of energy transfer driven by temperature difference. it is dissipative and often chaotic

heat

Another process of energy transfer, associated with organized change.

work

A property of a system, indicating the average kinetic energy of its particles.

temperature

an increase in temperature indicates an increase in various forms of energy in the system:

rotational, vibrational, kinetic energy