Johnny Jumper's favorite trick is to step out of his 16th story window and fall 50.0 m into a pool. A news reporter takes a picture of 73.5 kg Johnny just before he makes a splash, using an exposure time of 3.95 ms. a) Find Johnny's de Broglie wavelength at this moment. b) Find the uncertainty of his kinetic energy measurement during such period of time. c) Find the percent error caused by such an uncertainty.

An alpha particle with kinetic energy 12.5 mev makes a collision with lead nucleus, but it is not "aimed" at the center of the lead nucleus, and has an initial nonzero angular momentum (with respect to the stationary lead nucleus) of magnitude l = p0 b, where p0 is the magnitude of the initial momentum of the alpha particle and b=1.40×10−12 m. (assume that the lead nucleus remains stationary and that it may be treated as a point charge. the atomic number of lead is 82. the alpha particle is a helium nucleus, with atomic number 2.) what is the distance of closest approach?