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.

Karen is running forward at a speed of 9 m/s. she tosses her sweaty headband backward at a speed of 20 m/s. the speed of the headband, to the nearest whole number relative to a stationary observer watching karen

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?

Coal contains energy. a. light b. kinetic c. chemical d. mechanical