Consider, quantum mechanically, a stream of non-interacting particles of mass m each moving along the positive x direction (i. e., from left to right) with kinetic energy e=+v_0/2 toward a rectangular potential barrier given by v(x)=+ v_0 in the region -a1. with v_0=2ev, how wide must be the barrier so that the transmission probability is 10^-3.

How are calculation for velocity and speed different

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 790 n/m. it is initially at rest on an inclined plane that is at an angle of 28 degrees with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is k = 0.14. in the initial position, where the spring is compressed by a distance of a = 0.18 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Which system of units is used by only a small number of countries in the world, including the u.s.