<< Chapter < Page Chapter >> Page >

Conceptual questions

Why is a PET scan more accurate than a SPECT scan?

Got questions? Get instant answers now!

Isotopes that emit α radiation are relatively safe outside the body and exceptionally hazardous inside. Explain why.

Alpha particles do not penetrate materials such as skin and clothes easily. (Recall that alpha radiation is barely able to pass through a thin sheet of paper.) However, when produce inside the body, neighboring cells are vulnerable.

Got questions? Get instant answers now!

Ionizing radiation can impair the ability of a cell to repair DNA. What are the three ways the cell can respond?

Got questions? Get instant answers now!


What is the dose in mSv for: (a) a 0.1-Gy X-ray? (b) 2.5 mGy of neutron exposure to the eye? (c) 1.5m Gy of α exposure?

Got questions? Get instant answers now!

Find the radiation dose in Gy for: (a) A 10-mSv fluoroscopic X-ray series. (b) 50 mSv of skin exposure by an α emitter. (c) 160 mSv of β and γ rays from the 40 K in your body.

Gy = Sv RBE : a. 0.01 Gy; b. 0.0025 Gy; c. 0.16 Gy

Got questions? Get instant answers now!

Find the mass of 239 P u that has an activity of 1.00 μCi .

Got questions? Get instant answers now!

In the 1980s, the term picowave was used to describe food irradiation in order to overcome public resistance by playing on the well-known safety of microwave radiation. Find the energy in MeV of a photon having a wavelength of a picometer.

1.24 MeV

Got questions? Get instant answers now!

What is the dose in Sv in a cancer treatment that exposes the patient to 200 Gy of γ rays?

Got questions? Get instant answers now!

One half the γ rays from 99 m T c are absorbed by a 0.170-mm-thick lead shielding. Half of the γ rays that pass through the first layer of lead are absorbed in a second layer of equal thickness. What thickness of lead will absorb all but one in 1000 of these γ rays?

1.69 mm

Got questions? Get instant answers now!

How many Gy of exposure is needed to give a cancerous tumor a dose of 40 Sv if it is exposed to α activity?

Got questions? Get instant answers now!

A plumber at a nuclear power plant receives a whole-body dose of 30 mSv in 15 minutes while repairing a crucial valve. Find the radiation-induced yearly risk of death from cancer and the chance of genetic defect from this maximum allowable exposure.

For cancer: ( 3 rem ) ( 10 10 6 rem · y ) = 30 10 6 y , The risk each year of dying from induced cancer is 30 in a million. For genetic defect: ( 3 rem ) ( 3.3 10 6 rem · y ) = 9.9 10 6 y , The chance each year of an induced genetic defect is 10 in a million.

Got questions? Get instant answers now!

Calculate the dose in rem/y for the lungs of a weapons plant employee who inhales and retains an activity of 1.00 μ Ci 239 Pu in an accident. The mass of affected lung tissue is 2.00 kg and the plutonium decays by emission of a 5.23-MeV α particle. Assume a RBE value of 20.

Got questions? Get instant answers now!

Additional problems

The wiki-phony site states that the atomic mass of chlorine is 40 g/mol. Check this result. Hint: The two, most common stable isotopes of chlorine are: 17 35 Cl and 17 37 Cl . (The abundance of Cl-35 is 75.8 % , and the abundance of Cl-37 is 24.2 % .)

atomic mass ( Cl ) = 35.5 g/mol

Got questions? Get instant answers now!

A particle physicist discovers a neutral particle with a mass of 2.02733 u that he assumes is two neutrons bound together.

(a) Find the binding energy.

(b) What is unreasonable about this result?

Got questions? Get instant answers now!

A nuclear physicist finds 1.0 μ g of 236 U in a piece of uranium ore ( T 1/2 = 2.348 × 10 7 y ). (a) Use the decay law to determine how much 236 U would had to have been on Earth when it formed 4.543 × 10 9 y ago for 1.0 μ g to be left today. (b) What is unreasonable about this result? (c) How is this unreasonable result resolved?

a. 1.71 × 10 58 kg ; b. This mass is impossibly large; it is greater than the mass of the entire Milky Way galaxy. c. 236 U is not produced through natural processes operating over long times on Earth, but through artificial processes in a nuclear reactor.

Got questions? Get instant answers now!

Questions & Answers

A Pb wire wound in a tight solenoid of diameter of 4.0 mm is cooled to a temperature of 5.0 K. The wire is connected in series with a 50-Ωresistor and a variable source of emf. As the emf is increased, what value does it have when the superconductivity of the wire is destroyed?
Rupal Reply
how does colour appear in thin films
Nwjwr Reply
in the wave equation y=Asin(kx-wt+¢) what does k and w stand for.
Kimani Reply
derivation of lateral shieft
James Reply
total binding energy of ionic crystal at equilibrium is
All Reply
How does, ray of light coming form focus, behaves in concave mirror after refraction?
Bishesh Reply
Refraction does not occur in concave mirror. If refraction occurs then I don't know about this.
What is motion
Izevbogie Reply
Anything which changes itself with respect to time or surrounding
and what's time? is time everywhere same
how can u say that
do u know about black hole
Not so more
Radioactive substance
These substance create harmful radiation like alpha particle radiation, beta particle radiation, gamma particle radiation
But ask anything changes itself with respect to time or surrounding A Not any harmful radiation
explain cavendish experiment to determine the value of gravitational concept.
Celine Reply
 Cavendish Experiment to Measure Gravitational Constant. ... This experiment used a torsion balance device to attract lead balls together, measuring the torque on a wire and equating it to the gravitational force between the balls. Then by a complex derivation, the value of G was determined.
For the question about the scuba instructor's head above the pool, how did you arrive at this answer? What is the process?
Evan Reply
as a free falling object increases speed what is happening to the acceleration
Success Reply
of course g is constant
acceleration also inc
which paper will be subjective and which one objective
normal distributiin of errors report
normal distribution of errors
acceleration also increases
there are two correct answers depending on whether air resistance is considered. none of those answers have acceleration increasing.
Acceleration is the change in velocity over time, hence it's the derivative of the velocity with respect to time. So this case would depend on the velocity. More specifically the change in velocity in the system.
photo electrons doesn't emmit when electrons are free to move on surface of metal why?
Rafi Reply
What would be the minimum work function of a metal have to be for visible light(400-700)nm to ejected photoelectrons?
Mohammed Reply
give any fix value to wave length
40 cm into change mm
Arhaan Reply
40cm=40.0×10^-2m =400.0×10^-3m =400mm. that cap(^) I have used above is to the power.
i.e. 10to the power -2 in the first line and 10 to the power -3 in the the second line.
there is mistake in my first msg correction is 40cm=40.0×10^-2m =400.0×10^-3m =400mm. sorry for the mistake friends.
40cm=40.0×10^-2m =400.0×10^-3m =400mm.
this msg is out of mistake. sorry friends​.
what is physics?
sisay Reply
why we have physics
Anil Reply
because is the study of mater and natural world
because physics is nature. it explains the laws of nature. some laws already discovered. some laws yet to be discovered.
physics is the study of non living things if we added it with biology it becomes biophysics and bio is the study of living things tell me please what is this?
physics is the study of matter,energy and their interactions
all living things are matter
why rolling friction is less than sliding friction
thanks buvanas

Get the best University physics vol... course in your pocket!

Source:  OpenStax, University physics volume 3. OpenStax CNX. Nov 04, 2016 Download for free at http://cnx.org/content/col12067/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'University physics volume 3' conversation and receive update notifications?