Question 6 (1 point) An observer standing by the roadside noted a truck is travelling 18 m/s East while a cylinder inside the truck rolls to the back of the truck at 3
m/s West. Relative to the observer, how fast is the cylinder travelling?
оа 21 m/s
Ob
Ос
15 m/s
18 m/s
Od
3 m/s

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?