Physics Modern Physics Level: High School
Heisenberg’s Uncertainty Principle
Suppose the minimum uncertainty in the position of a particle is equal to its de Broglie wavelength . If the particle has an average speed of 4.9 x 10^5 m / s . What is the minimum uncertainty in its speed ?
Physics Modern Physics Level: High School
Heisenberg’s Uncertainty Principle
In the lungs there are tiny sacs of air , which are called alveoli . The average diameter of one of these sacs is 0.23 mm . Consider an oxygen molecule (mass = 5.3 x 10^-26 kg ) trapped within a sac . What is the minimum uncertainty in the velocity of this oxygen molecule ?
Physics Modern Physics Level: High School
Diffraction
Neutrons (m = 1.67 x 10^-27 kg ) are being emitted by two objects . The neutrons are moving with a speed of 2.47 x 10^3 m / s and pass through a circular aperture whose diameter is 0.120 mm. This situation is analogous to that shown in the figure at “click here” . According to the Rayleigh criterion , what is the minimum angle theta min (in radius) between the two objects , such that they are just resolved using neutrons ?
Physics Modern Physics Level: High School
Compton Effect
The X- rays detected at a scattered angle of theta = 153 degrees in the figure which is shown at “click here” have wavelength of 0.1867 nm . Find each of the following .a) the wavelength of an incident photon
b) the energy of an incident photon
c) the energy of a scattered photon
d) the kinetic energy of the recoil electron
Physics Modern Physics Level: High School
Compton Effect
An incident X-ray photon of wavelength 0.2800 nm is scattered from an electron that is initially at rest . The photon is scattered at an angle of theta = 180.0 degrees in Figure which is Shown at “click here" and has a wavelength of 0.2859 nm . Use the conservation of linear momentum to find the momentum gained by the electron
Physics Modern Physics Level: High School
Compton Effect
An X-ray photon is scattered at an angle of theta = 180 degrees , from an electron that is initially at rest . After scattering , the electron has a speed of 4.67 x 10^6 m/s . Find the wavelength of the incident X-ray photon .
Physics Modern Physics Level: High School
Dual Nature
An electron and a proton have the same speed . What is the ratio wavelength electron / wavelength proton of their de Broglie wavelengths ?
Physics Modern Physics Level: High School
Heisenberg’s Uncertainty Principle
Suppose the minimum uncertainty in the position of a particle is equal to its de Broglie wavelength . If the particle has an average speed of 4.5 x 10^5 m / s . What is the minimum uncertainty in its speed ?
Physics Modern Physics Level: High School
Dual Nature
In a television picture tube the electron are accelerated from rest through a potential difference V . Just before an electron strikes the screen , its de Broglie wavelength is 1.0 x 10^-11 m . What is the potential difference ?
Physics Modern Physics Level: High School
Diffraction
Neutrons (m = 1.67 x 10^-27 kg ) are being emitted by two objects . The neutrons are moving with a speed of 2.80 x 10^3 m/s and pass through a circular aperture whose diameter is 0.100 mm . This situation is analogous to that for light . According to the Rayleigh criterion , what is the minimum angle theta min (in radians) between the two objects , such that they are just resolved using neutrons ?
Physics Modern Physics Level: High School
Dual Nature
The X-rays detected at a scattering angle of theta = 163 degrees have a wavelength of 0.1867 nm . Finda) the wavelength of an incident photon
b) the energy of an incident photon
c) the energy of a scattered photon
d) the kinetic energy of the recoil electron . (For accuracy , use h = 6.626 x 10^-24 J*s and c = 2.998 x 10^8 m/s .
Physics Modern Physics Level: High School
It is calculated that the number of photons per second given off by a sixty-watt incandescent light bulb is 3.6 x 10^18 photons / s . The photons are emitted uniformly in all directions . From a distance of 3.1 m you glance at this bulb for 0.10 s . The light from the bulb travels directly to your eye and does not reflect from anything . The pupil of the eye has a diameter of 2.0 mm . How many photons enter your eye ?
Physics Modern Physics Level: High School
Photoelectric Effect
Radiation with a wavelength of 238 nm shines on a metal surface and ejects electrons that have a maximum speed of 3.75 x 10^5 m/ s . Which one of the following metals is it , the values in parentheses being the work functions : potassium (2.24 eV) , calcium (2.71 eV) , uranium (3.63 eV), aluminum(4.08 eV) , or gold (4.82 eV) .
Physics Modern Physics Level: High School
A hypothetical atom has four energy states as shown in the figure at “click here" Which of the following photon energies Ev could not be found in the emission spectra of this atom after it has been excited to the n = 4 state ?
1) Ev = 5 eV
2) Ev = 4 eV
3) Ev = 1 eV
4) Ev = 3 eV
5) Ev = 2 eV
Physics Heat & Thermodynamics Level: High School
The cosmic background radiation is that of a black body at 2.7 K . What is the value lamda max at which the distribution has a maximum ? Answer in units of mm .
