A beam of 3-MeV photons with intensity 108 cm−2 s −1 irradiates a small sample of water. (a) How many photon-water interactions occur in one second in one cm3 of the water? (b) How many positrons are produced per second in one cm3 of the water? 13. Shultis, J. Kenneth; Faw, Richard E.. Fundamentals of Nuclear Science and Engineering (p. 219). CRC Press. Kindle Edition.

Astudent pushes a 60-n block across the floor for a distance of 10 m. how much work was done to move the block

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length (in m) of a column of water 1.45 km high for a temperature increase of 1.12°c. assume the column is not free to expand sideways. as a model of the ocean, that is a reasonable approximation, as only parts of the ocean very close to

The nuclear potential that binds protons and neutrons in the nucleus of an atom is often approximated by a square well. imagine a proton conned in an innite square well of length 105 nm, a typical nuclear diameter. calculate the wavelength and energy associated with the photon that is emitted when the proton undergoes a transition from the rst excited state (n 2) to the ground state (n 1). in what region of the electromagnetic spectrum does this wavelength belong?