A42-g firecracker is at rest at the origin when it explodes into three pieces. the first, with mass 12 g, moves along the x-axis at 35 m/s. the second, with mass 21 g, moves along the y-axis at 29 m/s. find the velocity of the third piece.

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?