Concepts from Practice Test Flashcards
What speed do satellite radio signals travel in space?
3 x 10^8 m/s because it is a EM radiation
Why does a GPS radio signal travel slower through Earth’s atmosphere than through space?
Because the atmosphere has a larger index of refraction than the space/vacuum, so the velocity of the radio wave gets affected by this change in medium
What are the units for K (spring constant)?
kg / s^2
F = -Kx N = kg * m/s^2 = K * m K = kg/s^2
What are the units of specific heat?
J/(kgKelvins) or J/(gCelsius) or cal/(g*Celsius)
When does translation equilibrium occur?
translational equilibrium occurs when the sum
of external forces on an object is zero
When does rotational equilibrium occur?
When the sum of external torques is zero
Is arterial blood pressure measured to be higher in the arm or legs?
Higher in leg
How does density and mass change on the Moon (with a gravitational force 1/6 of Earth) compared to Earth?
Trick question! It doesn’t change.
How does the wave velocity change when light and sound travel through different media?
Since light is a transverse wave and sound is a longitudinal wave, we must consider them separately. When light goes from a gas to a solid, it experiences a decrease in velocity. Why? We know this because of our understanding of the index of refraction—light travels fastest through a vacuum and slows down in any other material (to be precise, the new speed of light in a medium will be equal to the speed of light in a vacuum, c, divided by the index of refraction of
the medium). We can thus eliminate choices (A) and (C). The speed of the longitudinal, or compression, wave
of sound, on the other hand, is increased in the glass, due to the closer proximity of the atoms in the medium that is being compressed. Since the wavelength will increase when sound travels from air to glass, so will its
speed. Note that the frequency of a wave will always stay constant when traveling from one medium to another, both in sound and light waves.
If the speed of a charged particle is increased by a factor of 2, the electrical force on the particle will change by what factor?
Trick question!
Electrical force does not depend on the particles velocity, it depends on the charge and electric field it feels.
How is capacitance related to the area and separation distance of the plates?
Capacitance is proportional the the plate’s area and inversely proportional to the separation distance. Also don’t forget, capacitance only depends on geometric factors!
What is the restoring force in a pendulum?
Gravitational force
How do you find wave speed (v)?
v = wavelength * freqeuncy
Does sound travel fastest in air, liquid, solid, or same in all?
Solid
Why does light travel more slowly through an dense medium than a vacuum?
The atomic structure of the dense medium absorbs and re-emits the light so it slows down light.
