SAT Physics Practice Test: Modern Physics

1. What’s the energy of a photon whose wavelength is 2.07 nm ?

(A) 60 eV
(B) 600 eV
(C) 960 eV
(D) 6,000 eV
(E) 9,600 eV

2. A metal whose work function is 6.0 eV is struck with light of frequency 7.2 x 10¹⁵ Hz. What is the maximum kinetic energy of photoelectrons ejected from the metal’s surface?

(A) 7 eV
(B) 13 eV
(C) 19 eV
(D) 24 eV
(E) No photoelectrons will be produced.

3. An atom with one electron has an ionization energy of 25 eV. How much energy will be released when the electron makes the transition from an excited energy level, where E= -16 eV, to the ground state?

(A) 9eV
(B) 11 eV
(C) 16 eV
(D) 25 eV
(E) 41 eV

4. The single electron in an atom has an energy of -40 eV when it’s in the ground state, and the first excited state for the electron is at -10 eV. What will happen to this electron if the atom is struck by a stream of photons, each of energy 15 eV ?

(A) The electron will absorb the energy of one photon and become excited halfway to the first excited state, then quickly return to the ground state, without emitting a photon.
(B) The electron will absorb the energy of one photon and become excited halfway to the first excited state, then quickly return to the ground state, emitting a 15 eV photon in the process.
(C) The electron will absorb the energy of one photon and become excited halfway to the first excited state, then quickly absorb the energy of another photon to reach the fast excited state.
(D) The electron will absorb two photons and be excited to the first excited state.
(E) Nothing will happen

5. What isthede Broglie wavelength of a proton whose linear momentum has a magnitude of 3.3 x 10^-23 kg·m/s ?

(A) 0.0002 nm
(B) 0.002 nm
(C) 0.02 nm
(D) 0.2 nm
(E) 2nm

6. The difference between the mass of an intact phosphorus-31 nucleus and the sum of the masses of its individual protons and neutrons is 0.2825 u. What is the nuclear binding energy per nucleon?

(A) 4.6 MeV/nucleon
(B) 6.3 MeV/nucleon
(C) 8.5 MeV/nucleon
(D) 12.1 MeV/nucleon
(E) 17.4 MeV/nucleon

7. Compared to the parent nucleus, the daughter of a β-decay has

(A) the same mass number but a greater atomic number
(B) the same mass number but a smaller atomic number
(C) a smaller mass number but the same atomic number
(D) a greater mass number but the same atomic number
(E) None of the above

8. The reaction  is an example of what type of radioactive decay?

(A) alpha
(B) β^-
(C) β⁺
(D) electron capture
(E) gamma

9. Tungsten-176 has a half-life of 2.5 hours. After how many hours will the disintegration rate of a tungsten-176 sample drop to its initial value?

(A) 5
(B) 8.3
(C) 10
(D) 12.5
(E) 25

10. What’s the missing particle in the following nuclear reaction?

(A) Proton
(B) Neutron
(C) Electron
(D) Positron
(E) Deuteron

11. What’s the missing particle in the following nuclear reaction?

(A) Proton
(B) Neutron
(C) Electron
(D) Positron
(E) Gamma

12. Two spaceships are traveling directly toward each other, one traveling at a speed of g and the other c/6 at a speed of c/3, as measured by observers on a nearby planet Hie faster ship emits a radar pulse directed toward the approaching ship. What is the speed of this radar pulse, as measured by observers on the planet?

(A) c/2
(B) 5c/6
(C) c
(D) 7c/6
(E) 3c/2

13. An Imperial battle cruiser, sitting in a hanger deck, is measured to have a length of 200 m by a worker on the deck. If the cruiser travels at a speed of (0.5*√3)c past a planet, what will be the length of the cruiser, as measured by the inhabitants of the planet?

(A) 50 m
(B) 87 m
(C) 100 m
(D) 173 m
(E) 400 m

14. An astronaut lives on a spaceship that is moving at a speed of 4c/5 away from the earth. As measured by a clock on the spaceship, the time interval between her maintenance checks on the ship’s main computer is 15 months. In the reference frame of the team here on Earth that monitors the ship’s progress, what is the time interval between maintenance checks on the ship’s main computer?

(A) 9 months
(B) 12 months
(C) 19 months
(D) 25 months
(E) 30 months

15. A particle whose rest energy is E is traveling at a speed of 12c/13. What is the particle’s kinetic energy?

(A) 7E/169
(B) 5E/13
(C) 3E/5
(D) 8E/5
(E) 13E/5