1. Intro to Physics Units

It has become popular for some people to have yearly whole-body scans (CT scans, formerly called CAT scans) using x rays, just to see if they detect anything suspicious. A number of medical people have recently questioned the advisability of such scans, due in part to the radiation they impart. Typically, one such scan gives a dose of $12$ mSv, applied to the whole body. By contrast, a chest x ray typically administers $0.20$ mSv to only $5.0$ kg of tissue. How many chest x rays would deliver the same total amount of energy to the body of a $75$-kg person as one whole-body scan?

In a diagnostic x-ray procedure, $5.00\times {10}^{10}$ photons are absorbed by tissue with a mass of $0.600$ kg. The x-ray wavelength is $0.0200$ nm.

(a) What is the total energy absorbed by the tissue?

(b) What is the equivalent dose in rem?

Calculate the energy released in the fusion reaction: ${}_2^{3}He{+}_1^{2}H{\to }_2^{4}He{+}_1^{1}H$

A proton and an antiproton annihilate, producing two photons. Find the energy, frequency, and wavelength of each photon if the $p$ and $\overline{p}$ collide head-on, each with an initial kinetic energy of $620$ MeV.

The starship Enterprise, of television and movie fame, is powered by combining matter and antimatter. If the entire $400$-kg antimatter fuel supply of the Enterprise combines with matter, how much energy is released? How does this compare to the U.S. yearly energy use, which is roughly $1.0\times {10}^{20}$ J?

In Example $44.3$, it was shown that a proton beam with an $800$-GeV beam energy gives an available energy of $38.7$ GeV for collisions with a stationary proton target. In a colliding-beam experiment, what total energy of each beam is needed to give an available energy of $2(38.7$ GeV$)=77.4$ GeV?

You work for a start-up company that is planning to use antiproton annihilation to produce radioactive isotopes for medical applications. One way to produce antiprotons is by the reaction $p+p\to p+p+p+\bar{p}$ in proton-proton collisions. You first consider a colliding-beam experiment in which the two proton beams have equal kinetic energies. To produce an antiproton via this reaction, what is the required minimum kinetic energy of the protons in each beam?

A $K^{+}$ meson at rest decays into two $p$ mesons. What are the allowed combinations of ${\pi }^0$ , ${\pi }^{+}$, and ${\pi }^{-}$ as decay products?

How much energy is released when a ${\text{µ}}^{-}$ muon at rest decays into an electron and two neutrinos? Neglect the small masses of the neutrinos.

Table $44.3$ shows that a ${\Sigma }^0$ decays into a ${\Lambda }^0$ and a photon. Calculate the energy of the photon emitted in this decay, if the ${\Lambda }^0$ is at rest.

Table $44.3$ shows that a $Σ^0$ decays into a ${\Lambda }^0$ and a photon. What is the magnitude of the momentum of the photon? Is it reasonable to ignore the final momentum and kinetic energy of the ${\Lambda }^0$? Explain.

If a ${\Sigma }^{+}$ at rest decays into a proton and a ${\pi }^0$, what is the total kinetic energy of the decay products?

What is the total kinetic energy of the decay products when an upsilon particle at rest decays to $r^{+}+r^{-}$?

The spectrum of the sodium atom is detected in the light from a distant galaxy. Use the Hubble law to calculate the distance of the galaxy from the earth.

Show that the product RC has units of s.