Recent content by mclame22

A beam of 11 eV electrons is directed towards a barrier of potential Vo = 3.8 eV. Compute the width of the barrier for which the reflection is maximized (Note: this is NOT asking for when reflection is 100%). Transmission probability for E > Vo: T = [ 1 + (Vo²*sin²(βa))/(4E*(E - Vo)) ]^(-1)...

I'm sorry, but I still can't see how to find Td... Your equations seem essentially the same as mine.

Homework Statement Show that the net work done by the otto engine per cycle is Cv(Tc - Tb)(1 - Ta/Tb) PV diagram: [PLAIN]http://www.antonine-education.co.uk/physics_a2/options/module_7/topic_4/Otto_indic.gif Homework Equations Work done by a kmole of gas expanding irreversibly and...

ψ(x) = A/(x - ik) over the region x = -∞ to ∞ A and k are constants, and i is √-1. I'm not sure if this is a valid wave function or not. I know that ψ must be continuous "everywhere," but this function does not exist for x = ik. But x only takes on the form of real numbers over the interval...

The thermal conductivity of wood is 1 BTU per hour, per square foot, for a temperature gradient of 1 F° per inch. Convert this to units of W/mK, knowing 1 F° = 5/9 C° 1 inch = 0.0254 m 1 foot = 0.3048 m 1 lb = 0.453593 kg 1 kcal = 4184 JI know there are conversions between BTU and...

I know this is a very old post, but using hage567's method works. The mass does not change, and using his expression gives the correct answer.

Homework Statement A particle's position is given by the formula r(t) = Rcos(ωt)î + Rsin(ωt)ĵ The particle's motion at t=0 can be described as a circle starting at time t=0 on the positive x axis. a) When does the particle first cross the negative x axis? b) Find the speed of the particle at...

Quinzio: I did take the +5.0m/s^2 acceleration into consideration for when the engine was on.. Then the helicopter was under the influence of gravity alone when the engine cut off. Thanks Delphi51, I did do a few calculations wrong. I ended up getting an answer of 180m which was correct. Thank...

Homework Statement A helicopter carrying Dr. Evil takes off with a constant upward acceleration of 5.0m/s². Secret agent Austin Powers jumps on just as the helicopter lifts off the ground. After the two men struggle for 10.0s, Powers shuts off the engine and steps out of the helicopter...

Homework Statement Consider a vertical cone of height h whose horizontal cross-section is an ellipse and whose base is the ellipse with major and minor semi-axes α and β. Verify that the volume of the cone is παβh/3. [ Hint: The area of an ellipse with major and minor semi-axes α and β is...