Electric Potential Problems Need Help

AI Thread Summary
The discussion revolves around solving various electric potential problems related to an x-ray tube, a-particles, hydrogen atoms, and capacitors. Key calculations include determining the work done on an electron moving from the cathode to the anode, the kinetic energy of an a-particle as it accelerates between two potentials, and the change in electric potential energy when forming a hydrogen atom. Additionally, the discussion addresses the number of electrons transferred in a capacitor charging process and the potential difference needed for a capacitor with a dielectric to match the energy of an empty capacitor. Participants emphasize the importance of showing work for assistance and note technical issues with the forum.
chillaxin
Messages
5
Reaction score
0
Electric Potential Problems Need Help ASAP!

The anode (positive terminal) of an x-ray tube is at a potential of +125000V with respect to the cathode (negative terminal). a) how much work (in Joules) is done by the electric force when an electron is accelerated from the cathode to the anode? b) if the elctron is intially at rest, what kinetic energy does the electron have when it arrives at the anode?


Point A is at a potential of +250V, and point B is at a potential of -150V. An a-particle is a helium nucleus that contains two protons and two neutrons: the neutrons are electrically neutral. An a-particle starts from rest at A and accelerates toward B. When the a-particle arrives at B, what kinetic energy (in elctron volts) does it have?


An electron and a proton are intially very far apart (effectively an infinite distance apart). They are then brought together to form a hydrogen atom, in which the electron orbits the proton at an average distance of 5.29x10^-11m. What is the EPE(final)-EPE(initial+) which is the change in the electric potential energy?

A capacitor has a capacitance of 2.5x10^-8 F. In the charging process, electrons are removed from one plate and placed on teh other plate. When the potential difference between the plates is 450V, how many electrons have been transferred?

Two capacitors are identical, except that one is empty and the other is filled with a dielectric (k=4.50). The empty capacitor is connected to a 12.0V battery. What must be the potential difference across the plates of the capacitor filled with a dielectric such that it stores the same amount of electical energy as the empty capacitor?
 
Physics news on Phys.org
-1- Hint -- Look up the energy conversion from electron volts (eV) to joules (J).

On the others, you need to show some work in order for us to help you.
 
What hapened to my post? I had made a post containing a link to the following thread:

https://www.physicsforums.com/showthread.php?t=135303

And emphasizing the rules of the forum according to which you must show some work in order get help.
 
quasar987 said:
What hapened to my post?
The PF has been up and down over the past few days. Probably it crashed about the time you posted?
 
I found out. It's just that our friend chillaxin has made the exact same post one the 'Advanced Physics' forum. :p
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top