If love is the answer, then what is the question?

What is the momentum of a 2 kg object moving at 15 meters per second

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?

During cooling, the kinetic energy of the molecules falls. why does this happen? a. the motion of the molecules increases. b. the motion of the molecules slows down. c. the van der waals forces between molecules decrease d. the forces of attraction between the molecules are overcome.