P114 – End material study guide
Nuclear Physics
- Calculate the binding energy/nucleon for 4He. Prove that it would require a net input of energy to transform 4He into (2) 2H nuclei. How much energy would it require?
- What is a half-life? What is a nuclear decay constant? What is an isotope?
- Derive the relation between the half-life and the nuclear decay constant.
- Roughly what is the radius of a germanium nucleus (a=70)?
- In terms of your health and assuming substances with similar activities (what is meant by activity?) … would it be better to (a) sit on a gamma source while drinking water laced with an alpha source or (b) sit on an alpha source while drinking water laced with a gamma source??
- What other things would determine the ultimate damage to your health if you had to do one of the above?
- Complete the following (a) 27Si -> 27Al + ?; (b) 228U-> a
+ ? ;
(c) 24Na -> e- + ?; (d) 24Na* -> 24Na +?.
- What are the uses of "labeling compounds" in medicine and biological research? Labeling is the process of substituting a naturally radioactive isotope in place of a normally stable isotope in a particular position in a chemical compound.
- A certain internal organ absorbs compound X. If you wanted to study the rate at which the organ assimilates compound X, would you label the compound X material with a gamma source or an alpha source? If you wanted to destroy the internal organ (because it is cancerous), would you label the compound X with an alpha or gamma source?
- Read section 45-6. I won’t ask a question on the exam about it … but the information is relevant and important to many of you.
- If you are of average mass, about 360 million nuclei in your body undergo radioactive decay each day. Express you activity in curies.
- A blood sample labeled with a radioactive material decays at a rate of 548 per second at t=0. At t=48 minutes, the counting rate has fallen to 213 per second (a) What is the half-life of the sample? What it its decay constant? (c) What will be the counting rate at t=125 minutes?
Relativity
- In the year 2020 a spacecraft flies over Moon Station III at a speed of 0.800c. A scientist on the moon measures the length of the moving spacecraft to be 86.5 m. The spacecraft later lands on the moon, and the same scientist measures the length of the now stationary spacecraft. What value does she measure?
- The subatomic particle known as a positive pion (p
+) is unstable, and lives on average 2.6x10-8 s as measured in its rest frame (the frame of reference of the particle). A) If such a particle is moving with respect to the laboratory with a speed of 0.978c, what lifetime is measured in the laboratory? B) What distance, measured in the laboratory, does the particle move before decaying?
- A nuclear bomb containing 9.0 kg of plutonium explodes. The sum of the rest masses of the products of the explosion is less than the original rest mass by one part in 104. A) How much energy is released in the explosion? B) If all this energy was harnessed and converted with 100% efficiency into electric power, how many 100 Watt lightbulbs could it keep lit for 1 year.