Conservation laws, mass-energy and antimatter Quiz
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5 questions, one answer each
Each answer is checked as you go, with why.
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1. The rest energy of a proton is 938 MeV. In joules this is about
- A. 1.5 × 10⁻¹⁰ J
- B. 1.5 × 10⁻¹³ J
- C. 1.5 × 10⁻¹⁶ J
- D. 9.4 × 10⁸ J
2. An electron and a positron at rest annihilate. The total energy of the photons produced is
- A. 0.511 MeV
- B. 1.02 MeV
- C. 0
- D. 2.04 MeV
3. Which of these is NOT conserved in a particle interaction?
- A. Charge
- B. Total energy
- C. Momentum
- D. Speed of each particle
4. A track in a bubble chamber starts at a point with no track leading to it and splits into two oppositely curving tracks. The parent was probably
- A. a neutral particle or photon
- B. a proton
- C. an electron
- D. a positron
5. Why must the electrons used to probe a proton have very high energy?
- A. So that they are positive
- B. So that their de Broglie wavelength is very small
- C. So that they have a larger charge
- D. So that they have a smaller mass