MRI PHY 101 Wk 6-9 Comprehensive Concept Review Flashcards

Momentum depends on

mass & velocity

Impulse depends on

Force & time

The impulse-momentum theorem states that

An impulse = a change in momentum

Law of Conservation of Momentum

For an isolated system, initial momentum = final momentum

Bouncing off a surface requires the impulse to (increase/decrease) which therefore often causes the impact force to (increase/decrease)

increase; increase

Momentum is a (vector/scalar), which means it (can/cannot) cancel.

vector; can

If a heavy cannon fires a cannonball, the recoil speed of the cannon must be (more/less) because the cannon's mass is (more/less).

less; more

If a heavy cannon fires a cannonball initially at rest, the total momentum after the collision is

A. more for the cannonball than the cannon

B. less for the cannonball than the cannon

C. zero

zero

A soap bubble has an initial momentum of 1 kg-m/s and bursts midair. The final momentum of the soap particles after the burst is

A. zero

B. 1 kg-m/s

C. need more information

1 kg-m/s

A shopping cart rolls horizontally along a smooth floor. A backpack is dropped vertically into the cart. The mass of the cart (increases/decreases). In order to conserve momentum, the velocity of the cart must (increase/decrease).

increases; decrease

A tennis ball is thrown against a brick wall. Which experiences a greater impulse?

A. The tennis ball

B. The brick wall

C. The impulses are the same

The impulses are the same.

The primary purpose of an airbag is to (increase/decrease) force of impact by (increasing/decreasing) time of contact.

decrease; increasing

Work depends on

Force & distance

Work only happens if the applied force is in the (same/opposite) direction of motion.

same

Work would be doubled if _____________ is doubled.

A. force

B. distance

C. either of these

either of these

Power = ___________ / ____________

Work / Time

It would require (more/less) power to complete a task in less time.

more

Law of Conservation of Energy

Energy can neither be created nor destroyed

Mechanical Energy is the sum of

Gravitational Potential Energy and Kinetic Energy

Gravitational Potential Energy depends on

Mass, Acceleration of Gravity (g), and height

Kinetic Energy depends on

Mass and velocity squared

A roller coaster sitting at the top of its drop will have maximum _____________ energy.

gravitational potential

A roller coaster moving at the halfway point down its drop will have (the same, half as much, double) gravitational potential energy compared to the start of the drop.

half as much

A roller coaster moving at the halfway point down its drop will have (the same, half as much, double) kinetic energy compared to the bottom of the drop.

half as much

A roller coaster moving at the bottom of its drop will have maximum _____________ energy.

kinetic

A roller coaster moving at the bottom of its drop will have (maximum/minimum) speed.

maximum

If a vehicle doubles its speed, its kinetic energy

A. doubles

B. halves

C. stays the same

D. quadruples

quadruples

If a vehicle halves its speed, its kinetic energy

A. doubles

B. halves

C. becomes quartered

D. quadruples

becomes quartered

Gravitational potential energy depends on

A. Vertical height from the ground

B. The path an object made to get to its position above the ground

C. Both of these

Vertical height from the ground

Work-Energy Theorem

Work = a change in energy

For a machine, _________ in = _________ out

work; work

It is (possible/impossible) for a machine to be 100% efficient

impossible

Efficiency is calculated by

useful energy / total energy x100%

A machine is able to multiply force output by (increasing/decreasing) distance

decreasing

A machine's user puts in (more/less) force over (more/less) distance.

less; more

If an object's speed doubles, its momentum (doubles/quadruples) and its kinetic energy (doubles/quadruples)

doubles; quadruples

Machines can multiply

A. Force

B. Energy

C. Both of these

Force

If there is no net force in the direction of movement

A. Work is still done

B. There is no work done

There is no work done

All waves can be drawn back to a _______________ source.

vibrating

How do longitudinal waves oscillate?

In the same direction of travel

How do transverse waves oscillate?

At 90 degrees to the direction of travel

Sound is an example of a ____________ wave.

longitudinal

Light is an example of a ____________ wave.

transverse

Units of Wavelength

meters

Units of Period

Seconds

Units of Frequency

Hertz

Amplitude is (half/double) the height of a wave

half

If we measure how loud a sound is, we are measuring ____________.

amplitude

_____________ is independent of other wave properties.

Amplitude

In the same medium, an increase in frequency results in a(n) (increase/decrease) in wavelength.

decrease

An increase in frequency results in a(n) (increase/decrease) in period.

decrease

In the same medium, an increase in wavelength results in a(n) (increase/decrease) in frequency.

decrease

What determines the speed of a wave?

The medium

Wave speed can be calculated with wavelength / _____________.

period

Wave speed can be calculated with wavelength * _____________.

frequency

The crest to tough distance is the ___________ of a transverse wave.

height (NOT amplitude)

The crest to crest distance is the ___________ of a transverse wave.

wavelength

The trough to trough distance is the ___________ of a transverse wave.

wavelength

The period of a pendulum depends on ___________ & __________ only.

length & acceleration due to gravity (g)

A heavy lead ball and light ping pong ball of the same size each hang from a 10 cm string. Which has a longer period?

Both the same.

The longer the length of a pendulum the (longer/shorter) the period.

longer

The longer the length of a pendulum the (higher/lower) the frequency.

lower

If waves align (in/out of) phase, the result is constructive interference.

in

If waves align (in/out of) phase, the result is destructive interference.

out of

If a crest aligns with a (crest/trough), the result is constructive interference.

crest

If a crest aligns with a (crest/trough), the result is destructive interference.

trough

If a compression aligns with a (compression/rarefaction), the result is constructive interference.

compression

If a compression aligns with a (compression/rarefaction), the result is destructive interference.

rarefaction

Only the ______________ is affected when waves interfere.

amplitude

In a standing wave, nodes are points of (constructive/destructive) interference.

destructive

In a standing wave, anti-nodes are points of (constructive/destructive) interference.

constructive

A standing wave results from

a wave interfering with its reflection.

The Doppler Effect occurs when there is a perceived change in ____________.

frequency

True or False: The Doppler Effect affects the perceived amplitude of the sound source.

False. Frequency only.

The Doppler Effect is evident when there is relative ______________ between the source and observer.

movement

If an observer moves toward a sound source, the frequency of the sound (increases/decreases)

increases

An observer runs towards a sound source. The faster they run, the (higher/lower) the perceived frequency.

higher

The human hearing frequency range is _____ to ______ Hz.

20 to 20,000 Hz

Sounds below 20Hz are called

infrasounds

Sounds above 20,000 Hz are called

ultrasounds

True or False: Sound can travel in a vacuum

False

Sounds generally travels fastest in (gasses/liquids/solids)

solids

Sounds will travel faster in (lighter/heavier) gasses.

lighter

True or False: the speed of sound is constant in air.

False - the speed of sound depends on things like air temperature, pressure, elevation, etc.

(Low/High) frequency sounds travel farther than (low/high).

Low; high

Multiple echoes are called

Reverberations

If the air is hotter/less dense closer to the ground, sound will bend (upwards/downwards)

upwards

If the air is cooler/more dense closer to the ground, sound will bend (upwards/downwards)

downwards

Resonance

When forced vibrations match the natural frequency of a system. Amplitude increases.

Resonance requires (high/low) energy input

low

How to calculate beat frequency

The absolute value difference between two tone frequencies.

Beats result from _________________, when some compressions align with compressions and some compressions align with rarefactions.

interference

An echo is an example of sound (reflection/refraction)

reflection

The speed of sound in air in ideal conditions is about _________ m/s

330

Sound energy in air eventually dissipates into _____.

heat

Size, shape, and elasticity all affect an object's _______________ frequency.

natural

Radio waves are (light/sound) waves.

light

(Warm/Cool) air results in a faster sound.

Warm

Sound refraction only occurs if the sound wave has a change in _____________.

speed

This card contains...

absolutely no physics. Just a reminder that you're awesome, and you're going to crush this Final Exam!!!