Let's consider tunneling of an electron outside of a potential well. The formula for the transmission coefficient is Te-2L, where L is the width of the barrier and C is a term that includes the particle energy and barrier height. For a particular situation, if C 1.0 nm-1, and you find the tunneling coefficient is T-0.010 (1 % of the electron tunnels through the barrier), then what is the width of the barrier L? e-2CL, where Select the correct answer 1 of 3 attempts used

a.1.0 nm
b. 1.2 nm
c. 2.3 pm
d. 4.6 nm
e. 2.3 nm

If the force on an object is in the negative direction, the work it does on the object must be [2 points a) negative. b) positive c) the work could be either positive or negative, depending on the direction the object moves

The extremely high temperatures needed to trigger nuclear fusion are proposed to be generated by laser irradiating a spherical pellet of deuterium and tritium fuel of diameter 1.8 mm. (a) determine the maximum fuel temperature that can be achieved by irradiating the pellet with 200 lasers, each producing a power of 550 w. the pellet has an absorptivity 0.3 and emissivity 0.8.

As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.