Recent content by shahar weiss

since they are opposite in charge there would be a pulling force and not repulsive

Homework Statement Im being asked what is the minimum energy requiered for the process e + p -> nutrino + nutron assumptions are: 1. Kinetic energy of proton is much lower from his rest mass, not true for the electron. 2. border line case is when nutrino energy is close to zero...

Thank you very very much all of the helpers, i really appreciate it thank you

how can you know pressure is increasing from f to a? temp is increasing but on the same time maybe volume is decreasing so pressure can stay constant

i just thought of somehting else, i can know what's the entropy change in the diagram from point to point while knowing the temp diff in those 2 points. maybe this gives me the info of whether its expansion or comprassion

the image is at http://img547.imageshack.us/i/newbitmapimagez.jpg/ problem is i cannot decide when the system is comprassing and when its expanding

Homework Statement given the following diagram : http://www.freeimagehosting.net/uploads/… a)mention for every step if it is isothermal / adiabatic / else. does the system receive heat or emit heat. b)given this gas is ideal gas, sketch a diagram with respect to P and V c)calculate work done...

if i do I + II + III = 0 i do get a logic answer, approx 330 K. i see my mistake now Thank you very much D H and vela!

It is not writted in the question but i assume Heat cap is per 1K. here are math eqs. For copper: Q = M*cp*DeltaT = 31.47[mol]*24.44[J/mol*K] * (Tf-273) = 769.12*(Tf-273) (I) For water condensation Q = -dH = -40700 J (II) water cooling: Q = m*cp*DeltaT = 75.35 (Tf-373) (III) since...

when i say the heat from the copper should be equal to the heat from the water i mean that in absolute value it equal but ofcours they have different signs since what is giving heat and one is gainning heat. Q for water should be negative since they gave away heat. Q for copper should be...

when i say the heat from the copper should be equal to the heat from the water i mean that in absolute value it equal but ofcours they have different signs since what is giving heat and one is gainning heat. Q for water should be negative since they gave away heat. Q for copper should be...

The final temp of the copper should be higher than 273 k. something is wrong with my sollution since i get lower than 273. question is, where did i go wrong

Homework Statement 31.47mol of copper at 273 kelvin put inside an isolated cup along with 1 mol of water vapors at 373 Kelvin. (pressure is constant at 1 atm). ALL of the water condensed. given parameters: Cp(Cu(solid)) = 24.44 J/mol Cp(H20(gas) = 33.58 J/mol Cp(H20(liquid) = 73.35...

wont work here since there are two different half life times, two different activities, two different decay constants. your formula is good when there is simple decay from some amount of radiactive sample. here the sample's size changing all the time

Here's a ques. I am having problem with: sample of gold is bombard with 2*10^10 neutrons per sec. it cause the Au(A=197) become radioactive (Au(A=198)) which decay with half life time of 2.969day (through beta decay 1. how many Au(A=198) will be after 5 days of bombardment? 2. how many...