Recent content by Allens

Thankyou Tiny-Tim very helpful :D

yea but for the second equation,when u sub θ =90 torque would equal zero, however when you sub zero you get a value. But θ = 0 means the coil is parallel with mag field hence no torque :S

can you say that the Silver oxide cell (button cell) works on the same principles that the dry cell battery does? (similarities - differences) sorry but in my textbook the reduction reaction for manganese dioxide says: NH4+ + MnO2 + H2O + e- -----> Mn(OH)3 + NH3 whilst my other...

thanks a lot very helpful

OHHHHHHHH,, heheheh... i must have had a mental blank :), i get you now,, why would time dilate when your on Earth, when your not traveling at 0.97c the dilation that would occur would be the spacecraft , in which it is in the same frame of reference to 0.97c. It's actually common sense, why...

"the reduction reaction occurs within the moist paste comprised of ammonium chloride (NH4Cl) and manganese dioxide (MnO2): 2 NH4+ + 2 MnO2 + 2e- ------> Mn2O3 + 2 NH3 + H2O" [source: http://library.kcc.hawaii.edu/external/chemistry/everyday_battery.html ] i don't understand...

umm... can u simply put it into the equation t =d/v ? don't you need to use the time dilation equation? since the observer is not in the same frame of reference to the spacecraft (he is stationary therefore rest frame t0)? Tv= \time \equiv \frac{t0}{\sqrt{{45 - v^2/c^2}}

A certain star is 45.0 light-years away. How long would it take a spacecraft traveling at 0.97c to reach that star from Earth, as measured by an observer: (a) on Earth? (b) on the spacecraft ? i'm not sure how to solve this question... simply i don't know which is tv and which is t0. i...

thank you very much these links are very helpful :) much appreciated.

i'm sorry but I'm kind of confused. Can you tell me basically how the dry cell battery works in terms of chemical reactions such as "redox" reaction. (please include the reduction and oxidisation reactions, as well as the purpose of the salt bridge and the electrolyte). "In dry-cell...

OK thank you that was very helpful, i would also like to ask where in the battery does the manganese dioxide be reduced (i know the cathode, however i am unsure where the cathode physically is), also could you say the transfer of electrons through the anode to cathode via the electrolytes is...