http://www.ck12.org Chapter 23. Special and General Relativity Version 2
- Enterprise crew members notice that a passing Klingon ship moving 0.8 c with respect to them is engaged in
weapons testing on board. At the closest point of contact the Klingons are testing two weapons: one is a laser,
which in their frame moves atc; the other is a particle gun, which shoots particles at 0.6 c in the Klingon
frame. Both weapons are pointed in the same line as the Klingon ship is moving. Answer the following two
questions choosing one of the following options: A. V< 0 .6 c B. 0.6 c< V< 0 .8 c C. 0.8 c< V< c D.
c<V< 1 .4 c E. V> 1 .4 c F. V=c
a. Question 1: What speed,V, does the Enterprise measure the laser gun to achieve with respect to the
Enterprise?
b. Question 2: What speed,V, does the Enterprise measure the particle gun to achieve with respect to the
Enterprise? - How much energy is produced by a.5 kilogram softball?
- The isotope of silicon Si^31 has an atomic mass of 30.975362 amu. It can go through beta radioactivity,
producing P^31 with a mass of 30.973762 amu.
a. Calculate the total energy of the beta particle emitted, assuming the P^31 nucleus remains at rest relative
to the Si^31 nucleus after emission.
b. Another possibility for this isotope is the emission of a gamma ray of energy 1.2662 Mev. How much
kinetic energy would the P^31 nucleus gain?
c. What is the frequency and wavelength of the gamma ray?
a. What is the rebound velocity of the P^31 nucleus in the case of gamma ray emission?
Answers to Selected Problems
- longer
2.γ=∞, the universe would be a dot
3..
4..
5.γ= 1. 002
- 15 × 107 m/s
- a. 0.659 km b. 22.4 c. 4. 92 × 10 −^5 m/s d. 14.7 km
- 2900 m
- 34 × 10 −^57 m
- 0.303 s
11..
- 9 × 10 −^30 kg, yes harder to accelerate
- a. f b. c
- 5 × 1016 J; 1. 8 × 1013 softballs