Week 2 Homework Assignment

1. An electric field of 6.40V/m is desired between two parallel plates 11.0mm apart. How large a voltage should be applied?
2. What is the speed of (a) a 750-eV, and (b) a 3.5 -keV, electron?
3. (a) What is the electric potential a distance of 2.5 x 10^-15m away from a proton? (b) What is the electric potential energy of a system that consists of two protons 2.5 x 10^-15m apart?
4. An electron starts from rest 72.5cm from a fixed point charge with Q = -0.125mC. How fast will the electron be moving when it is very far away?
5. An electron and a proton are 0.53 x 10^-10m apart. What is their dipole moment if they are at rest?
6. The electric field between the plates of a paper-separated (K = 3.75) capacitor is 9.21 x 10⁴V/m. The plates are 1.95mm apart and the charge on each plate is 0.775mC. determine the capacitance of this capacitor and the area of each plate.
7. A homemade capacitor is assembled by placing two 9-in pie pan 10cm apart and connecting them to the opposite terminals of a 9-V battery. Estimate (a) the capacitance, (b) the charge on each plate, (c) the electric field halfway between the plates, (d) the work done by the battery to charge the plates. (e) Which of the above values change if a dielectric is inserted?