# Recent content by professor

1. ### Equation to relate voltage to distance of a spark

I need to calculate the minimum distance for which a charge of some voltage will jump. Is there any equation that relates distance of a spark jump to voltage (a fairly generalised equation will do, I dont need to worry about strange shapes of the charged bodies that the charge leaps between or...
2. ### Frictionless sphere, falling particle

Thanks, I got it now, the angle is the arccos of 2/3. I just used conservation of energy for the particle, and get mgh+mv^2/r =mgh+mv^2/r, then solved fo V^2 later by equating centripetal force with mgcos(x) so the net force would be 0, where the particle fell off of the sphere.
3. ### Frictionless sphere, falling particle

Homework Statement A particle initially sits on top of a large smooth sphere of radius R. The particle begins to slide down the sphere without friction. At what angle . does the particle lose contact with the sphere? Homework Equations g=9.8m/s2 perhaps? (Is this dependent on the...
4. ### Spring and falling body problem

1. Neglect air resistance. A suspention bridge spand the colorado river at a height of 321 meters. Consider a 75kg bungee jumper, and a 200m bungee cord which obeys hooke's law (once it reaches its unstreched length). a) calculate the spring constant k, so that the jumper halts just above...
5. ### Astrophysicist salary

Professor I am going to be an entering freshman in the field of astrophysics this coming year, personally, the reason that I find astrophysics to be both fun and fiscally sound as a decision, is because I plan to move out of the country, where physicians are payed significantly less (France...
6. ### Im thinking about building a cyclometer

Should i be able to replace those large stationary "dee" magnets with electromagntes? (or would that be a grand misuse of the powersupply, as i know i will need to supply an ample amount to the electron gun, and the current which i need to accelerate the particles, rather than simply keep them...
7. ### Getting a solution that contains 40% iodine

you should really attepmt the problem before posting here.. but- okay... how many litres of the 80% stuff is there.. thats the limiting, otherwise you might as well use 25 litres of it diluted with water to 50 litres or if you cant dilute with distilled water, like any reasonable...
8. ### Speed of an arrow from a bow

im not exactly an expert, but it seems to me like air ressistance and friction wont be flawing any simpler calcuations too greatly when your talking about the initial velocity, i wouldent even bother with them, mabye again thats because i cant exactly follow your equation, explain how you came...
9. ### Proton current

i was thinking over how a hydrogen fuel cell works, seperating the electrons and protons (into its ions like any other way of converting electrical enery to chemical) but i wondered if the protons as well as the electrons could be used as a current to creat a circuit such as the electrons do, or...
10. ### Forces affecting the path of a photon

the electromagnetic force would not affect the photons, because they are not charged, i see that much now, i also see that the splitting which may or may not happen would have an affect on the path of the photon, and perhaps lead to the seperation of it temporarily, but as another question...
11. ### Forces affecting the path of a photon

could anyone be so kind as to provide a list for me, im attempting to better a formulate a further question, but this list would be greatly helpful in my understandign of what i am trying to ask. the two i can easily think of are: 1.gravity 2.magnetism can anyone correct me if either...
12. ### Energy and gravity

in energy directly related to gravity as mass is, it seems that it should be according to relativity, but this leads me to the question of why dark matter need be proposed to explain the differences in gravity and mass proportionality of galaxy clusters and such. Is this difference not as simply...
13. ### Riddle game - Something for you scientists

so ehh.. how do i go about putting the answer the the impaler bit in... (the impaled inhabitants of i cant remember what city) ive tried all sorts of stuff... dead, impaled, corpses, bodies, undead all with and without the infront. nevermind that... i got it, i was thinking of the...
14. ### Ac vs dc power

which does an appliance sich as a ipod run off of..? i know verry little of such things =(
15. ### Medical Accelerating learning

I myself am in 10th grade in a public school, i had perviously been in a private school, and a seperate (full time) gifted schooling program. In school i have skipped two years of math (the only one to do so in 3+ years) as well as having skipped honors chem beofre taking ap chem a year before...