Quantum Mechanics Answers

Suppose an atom of Osmium at rest emits an X-ray photon of energy 6.8 keV. Calculate the

“recoil” momentum and kinetic energy of the atom.

A proton and an alpha particle attempt to penetrate a rectangular potential barrier of height

10 MeV and thickness 10-14m. Both particles have total energies of 5MeV. Use qualitative

arguments to predict which particle has the highest probability of succeeding and evaluate

quantitatively the probability of success of both particles.

a) A beam of 7.8-MeV α particles scatters from a gold foil of thickness 0.30 μm.

i) What fraction of the α particles is scattered between 1.5° and 2.5°?

ii) What is the ratio of α particles scattered through angles greater than 2° to the number

scattered through angles greater than 10°?

a) A beam of 7.8-MeV α particles scatters from a gold foil of thickness 0.30 μm.

i) What fraction of the α particles is scattered between 1.5° and 2.5°?

ii) What is the ratio of α particles scattered through angles greater than 2° to the number

scattered through angles greater than 10°?

In Rutherford scattering we noted that angular momentum is conserved. The angular

momentum of the incident α particle relative to the target nucleus is mv0b where m is the

mass, v0 is the initial velocity of the α particle, and b is the impact parameter.

Start with L = r x p and show that angular momentum is conserved, and the magnitude is

given by mv0b along the entire path of the α particle while it is scattered by the Coulomb

force from a gold nucleus

A proton and an alpha particle attempt to penetrate a rectangular potential barrier of height

10 MeV and thickness 10-14m. Both particles have total energies of 5MeV. Use qualitative

arguments to predict which particle has the highest probability of succeeding and evaluate

quantitatively the probability of success of both particles.

Suppose an atom of Osmium at rest emits an X-ray photon of energy 6.8 keV. Calculate the

“recoil” momentum and kinetic energy of the atom

An airplane flies 120 km at a constant altitude in a direction 30.0° north of east. A wind is blowing that results in a net horizontal force on the plane due to the air of 2.40 kN in a direction 10.0° south of west. How much work is done on the plane by the air?

Note on the meaning of 1E8 in answers: 1E8 is an alternative way to write "10 to the power of 8". So 1E8 is 100 000 000. It is a convenient notation when superscripts are difficult to accommodate.

A substance of mass 0.4kg having a density 2700kg/m3 occupies an area 0.02m2. Determine the thickness of the substance.

how much heat is needed to melt 1.5kg of ice and then to rise the temperature of the resulting water 500c?