Your friend Greg is planning to get in shape so he can try out for the football team next year. He has not exercised regularly since he injured his left knee over two years ago in a skateboarding accident, but he is planning an intense and vigorous exercise regimen. Write a letter to Greg giving him some advice on getting back into shape safely considering his past. << Read Less

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

Awave has a wavelength of 7 mm and a frequency of 19 hertz. what is its speed?

Ascientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). she aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). the index of refraction of water is 1.3