A cannonball has a horizontal velocity of 15 m/s and a vertical velocity of 19 m/s. Assume that up and to the right are the positive directions. Which of the following correctly describes the direction of the overall velocity of the cannonball at this point in time?

Aparticle of mass m is placed in a one-dimensional box of length l. the box is so small that the particle’s motion is relativistic, so that e p2/2m is not valid. (a) derive an expression for the energy levels of the particle using the relativistic energy–momentum relation and the quantization of momentum that derives from connement. (b) if the particle is an electron in a box of length l 1.00 1012 m, nd its lowest possible kinetic energy. by what percent is the nonrelativistic formula for the energy in error?