Studied by 0 People

0.0(0)

Get a hint

hint

Tags & Description

New cards239

Still learning0

Almost done0

Mastered0

239 Terms

New cards

Protons natural effect on each other is that they

repel each other

New cards

New cards

A proton's quark configuration is

Up, Up, Down (uud)

New cards

New cards

The charge of a proton is positive because

The sum of its quark's charges = 1 u = +2/3 d = -1/3 Configuration = uud = 2/3 + 2/3 - 1/3 = 3/3 = 1

New cards

New cards

The charge of a pion is positive because

The sum of its quark's charges = 1 u = +2/3 d^-(anti-down quark) = 1/3 Configuration = ud^- = 2/3 + 1/3 = 3/3 = 1

New cards

New cards

The charge of a neutron is neutral because

The sum of its quark's charges = 0 u = +2/3 d = -1/3 Configuration = udd = 2/3 - 1/3 - 1/3 = 0/3 = 0

New cards

New cards

An atom contains

a positively charged nucleus composed of protons and neutrons.

electrons that surround the nucleus

New cards

New cards

A nucleon is

a proton or neutron in the nucleus

New cards

New cards

Each electron has

a negative charge

New cards

New cards

The electrons are held in the atom by

the electrostatic force of attraction between the negatively charged electrons and the nucleus, due to the protons giving the nucleus a positive charge

New cards

New cards

The nucleus is ? times the size of the atom

0.00001 (one ten thousandth)

New cards

New cards

The charge of a particle is shown in

Coulombs (C)

New cards

New cards

The mass of a particle is measured in

Kilograms (kg)

New cards

New cards

An electron has ? compared to a proton

much less mass

opposite charge

New cards

New cards

A similarity between protons and neutrons is

their almost equal mass

New cards

New cards

Neutrons are

uncharged

New cards

New cards

An electron has a mass ? times smaller than a proton

2000

New cards

New cards

Atoms of the same ? (with the same number of ?) that have different numbers of ? are called ?

Atoms of the same *element* (with the same number of *protons*) that have different numbers of *neutrons* are called *isotopes*

New cards

New cards

Isotopes are

atoms with the same number of protons and a different number of neutrons

New cards

New cards

The total number of protons and neutrons in an atom is called

the nucleon number / mass number

New cards

New cards

Each type of nucleus is called

a nuclide

New cards

New cards

The specific charge of a charged particle =

charge / mass

New cards

New cards

A stable isotope has ? that do not ? so there must be ?. We call this the ? because it overcomes the ? between ?, keeping them together.

A stable isotope has *nuclei* that do not *disintegrate* so there must be *a force holding them together*. We call this the *strong nuclear force* because it overcomes the *electrostatic force of repulsion* between *protons and neutrons*, keeping them together.

New cards

New cards

10^-15 =

femto - fm

New cards

New cards

The electrostatic force between two charged particles has ? range but ?

The electrostatic force between two charged particles has *infinite* range but *the force decreases as the range increases*

New cards

New cards

The strong force is (range)

Attractive from 4fm to 0.5fm Closer than 0.5fm it becomes repulsive

New cards

New cards

In Young's double slit experiment:

d is ?

s is ?

Theta is ?

D is?

w is ?

d is gap separation

s is also gap separation

Theta is the angle from n = 0 to n = x

D is the distance from the gaps to the screen

w is the fringe spacing

New cards

New cards

What's the name given to a maximum on a standing wave

An antinode

New cards

New cards

For the first harmonic, in terms of length: wavelength =

2 L

New cards

New cards

The nth harmonic has length L given by

L = (n/2)wavelength

New cards

New cards

Points either side of the rest position in a standing wave are ?(phase)

180 degrees out of phase / antiphase

New cards

New cards

Points on the same side of the equilibrium position on a stationary wave are?(phase)

In phase

New cards

New cards

A progressive wave is

a wave that moves through the medium

New cards

New cards

When two waves meet they

Superpose

New cards

New cards

The frequency of the nth harmonic is given by

n * fundamental frequency

New cards

New cards

If the frequency of the first harmonic is 20Hz, the third has f =

60Hz

New cards

New cards

When labeling standing waves, antinodes are labeled ? and nodes are labeled ?

Antinodes : A

Nodes : N

New cards

New cards

Longitudinal waves differ from transverse in that

points on the wave oscillate in line with the direction the wave travels.

New cards

New cards

Two points on a progressive wave are one-eighth of a wavelength apart. The distance between them is 0.5 m, and the frequency of the oscillation is 10 Hz. What is the minimum speed of the wave?

40 m/s

Because if λ / 8 = 0.5 λ= 4 v = fλ v = 10 * 4 = 40 m/s

New cards

New cards

The speed of sound in water is 1500 m s−1. For a sound wave in water having frequency 2500 Hz, what is the minimum distance between two points at which the vibrations are 𝜋/3 rad out of phase?

0.1 m

v = fλ v / f = λ 1500 / 2500 = λ = 0.6 m λ = 2𝜋 𝜋/3 = λ/6 𝜋/3 = 0.6 / 6 = 0.1 m

New cards

New cards

A source emits light of wavelength 600 nm as a train of waves lasting 0.01 μs. How many complete waves are sent out? speed of light = 3 × 108 m/s

5 * 10^6

v = fλ v / λ = f (3 * 10^8) / (600 * 10^-9) = f = 5 * 10^14 If a clock ticks once a seconds then to find the number of ticks every half a second: 1 * 1/2 = 1/2 ticks per second

So (5 * 10^14) * (0.01 * 10^-6) = number of waves = 5 * 10^6

New cards

New cards

A progressive wave in a stretched string has a speed of 20 m s−1 and a frequency of 100Hz. What is the phase difference between two points 25 mm apart?

v = fλ v / f = λ 20 / 100 = λ = 0.2 m 25 * 10^-3 = 0.025 m 0.2 / 0.025 = 8 So the phase difference is an eight of a wavelength or 2pi/8 = pi/4 radians

New cards

New cards

Monochromatic light passes from air into water. The ? change but not the ?

The velocity and wavelength change but not the frequency

New cards

New cards

The least distance between two points of a progressive transverse wave which have a phase difference of 𝜋3 rad is 0.050 m. If the frequency of the wave is 500 Hz, what is the speed of the wave?

150 m/s

pi / 3 = 0.05 m 2pi = λ pi = 0.15 2pi = 0.3 = λ v = fλ v = 500 * 0.3 = 150 m/s

New cards

New cards

State the characteristic features of longitudinal waves

particle vibration (or disturbance or oscillation) (1) same as (or parallel to) direction of propagation (or energy transfer) (1)

New cards

New cards

State the characteristic features of transverse waves

(particle vibration) perpendicular to direction of propagation (or energy transfer) (1)

New cards

New cards

Explain how energy is transmitted in a sound wave.

particles in the transmitting medium are made to vibrate/given energy

or mention of a compression/region of increased pressure (or rarefaction) cause nearby particles to vibrate/have energy/move

or the compression produces a compression further along (the medium)

2

New cards

New cards

Define the amplitude of a wave.

maximum displacement from equilibrium/mean position/mid-point/etc (1)

New cards

New cards

Give examples of transverse waves

electromagnetic radiation (1) surface of water/water waves/in ripple tank (1) rope (1) slinky clearly qualified as transverse (1) secondary ('s') waves (1)

New cards

New cards

Differences between transverse and longitudinal waves

transverse wave: oscillation (of medium) is perpendicular to wave travel or transverse can be polarised or all longitudinal require a medium

New cards

New cards

Explain what is meant by the frequency of a wave.

number of (complete) waves (passing a point) in 1 second OR number of waves / time (for the waves to pass a point) OR (complete number of) oscillations \ vibrations per second OR 1 / T with T defined as time for 1 (complete) oscillation

New cards

New cards

A continuous ultrasound wave of constant frequency is reflected from a solid surface and returns in the direction it came from. Assuming there is no significant loss in amplitude upon reflection, describe and explain the effect the waves have on the particles in the medium between the transmitter and the solid surface.

• mention of nodes and antinodes • particles not moving at a node • maximum displacement at antinode • particles either side of node in antiphase / between two nodes in phase • variation of amplitude between node

New cards

New cards

Any process of creating ions is called

ionisation

New cards

New cards

?, ? and ? create ions when they pass through atoms

Alpha, beta and gamma radiation

New cards

New cards

? passing through a ? tube create ions with they collide with vapour in the tube

Electrons passing through a fluorescent tube create ions with they collide with vapour in the tube

New cards

New cards

An electron that moves through a potential difference of 2000V is ?eV

2000eV

New cards

New cards

An ion of charge +2e moves though a potential difference of 10V is ?eV

20

New cards

New cards

Atoms can absorb energy from colliding electrons without being ionized via

excitation

New cards

New cards

The energy values at which an atom absorbs energy are its

excitation energies

New cards

New cards

The lowest energy of an atom is called its

ground state

New cards

New cards

Excitation energy measurements are used to construct

an energy level diagram for the atom

New cards

New cards

When electrons move down an energy level a ? which is called ?

When electrons move down an energy level a photon is emitted which is called de-excitation

New cards

New cards

Acceleration of free fall is

The acceleration of an object acted on only by the force of gravity

New cards

New cards

Alpha radiation is

Particles that consist of two protons and two neutrons

New cards

New cards

A point on a stationary wave moves

up and down either side of the rest position / equilibrium position

New cards

New cards

Two points on a stationary wave, one either side of the rest position, have the phase relationship:

180 degrees out of phase

New cards

New cards

Two points on a stationary wave that are the same side of the rest position are

in phase

New cards

New cards

Halfway between two nodes is a

antinode

New cards

New cards

On a stationary wave, if L is 0.48m what is the wavelength?

0.96m wavelength = twice the distance between two nodes / antinodes where L is the distance between two nodes / antinodes

New cards

New cards

Stationary waves: Equation to find frequency of nth harmonic

f = (n * c) / 2L

New cards

New cards

A guitarist wants to increase the fundamental frequency of his strings, how might he do it?

Increase the tension

New cards

New cards

Define: fundamental frequency

the frequency of the first harmonic

New cards

New cards

frequency is

the number of full wave cycles per second

New cards

New cards

in longitudinal wave, points on the wave

oscillate in the axis of the wave's direction of travel

New cards

New cards

Total internal reflection occurs when

the angle of incidence is greater than the critical angle

New cards

New cards

equation for a wave passing between two materials, involving their refractive index and angles

n1 * sinANGLE1 = n2 * sinANGLE2

New cards

New cards

The critical angle is found using the equation:

n1 * sinANGLEc = n2 * sin90 Where ANGLEc is the critical angle, being reflected 90 degrees

New cards

New cards

An emitted photon has energy 9.92 * 10-19 J Calculate its wavelength

frequency = E / h wavelength = c / f so wavelength = c / E / h wavelength = ch / E wavelength = ((3 * 10^8) * (6.63 * 10^-34))/(9.92 * 10^-19) wavelength =

New cards

New cards

An electron with no excess energy is in ? state An electron with some excess energy is in ? state An electron with enough excess energy to leave an atom is in ? state

An electron with no excess energy is in its ground state (n = 1) An electron with some excess energy is in an excited state An electron with enough excess energy to leave an atom is in an excited state (n = infinite)

New cards

New cards

Work function equation

New cards

New cards

Intensity of light is

the number of photons striking a surface per second

New cards

New cards

What is the work function equal to?

the minimum energy required for an electron to be removed from a cold atom with 0 kinetic energy

New cards

New cards

In the work function what is Ek?

The maximum amount of kinetic energy has after escaping an atom

New cards

New cards

What kind of experiment would confirm that electrons have wave-like nature?

diffraction (through an atomic lattice)

New cards

New cards

why is it easier to demonstrate the wave properties of electrons than protons?

because electrons have less mass, so larger wavelengths

New cards