If Anyone Can Help Me With ANY Of These Problems.  Please Reply With A Post


1 - The electrons in a Tv picture tube are accelerated from rest through a potential difference of 25kV.  What is the speed of the electrons after they have been accelerated by this potential difference?

2 -   FIGURE:        -6.1 microC -------------------+2.7 microC

                             
                           


                            -3.3 microC --------------------


          Figure shows 3 charges at the corners of a rectangle.  -6.1 and -3.3 are 0.16m apart.  -6.1 and +2.7 are 0.25m apart.  (A) How much work must be done to move the +2.7 charge to infinity. (B) Suppose, instead, that we move the -6.1 charge to infinity.  Is the work required in this case greater than, less than, or the same as when we moved the +2.7 charge to infinity? Explain (C) Calculate the work needed to moe the -6.1 charge to infinity.


3 - A parallel plate capcitor filled with air has plates of area 0.0066 m^{2} and a seperation of 0.45 mm.  (A) Find the magnitude of the charge on each plate when the capacitor is connected to a 12V battery.  (B) Will the answer to part A increase, decrease, or stay the same if the seperation between the plates is increased? Explain. (C) Calculate the magnitude of the charge on the plates if the seperation is 0.90 mm

4 - The membrane of a livin cell can be approximated by a parallel-plate capacitor with plates of area 4.75 x 10^{-9} m^{2}, a plate seperation of 8.5X10^{-9}m and a dielectric with a dielectric constant of 4.5. (A) What is the energy stored in such a cell membrane if the potential difference across it is 0.0725V? (B) Would your answer to part (a) increase, decrease, or stay the same if the thicness of the cell membrane is increased? Explain.

5- The seperation between the plates of a parallel-plate capacitor is doubled and the area of the plates is halved.  How is the capacitance affected?