Practice Problems: Electric Potential
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1. (moderate) An electron is moving along an E-field. If the initial K for the motion was greater than zero, describe the following parameters: ΔK, ΔU, ΔV, Wfield
2. (moderate) Repeat question #1 with a proton instead of an electron.
3. (easy) If 5 C of charge are moved through a +5 v potential difference, determine the change in electric potential energy.
4. (easy) A negatively charged particle (q = -2 C) moves through a 2000 v loss of electric potential. Will there a loss or gain of electric potential energy? Will there be a loss or gain of kinetic energy? (Note: Electric force is a conservative force.)
5. (easy) A negative charge moves through an electric field such that it slows down, losing 100 J of kinetic energy. The change in electric potential experienced by the charge is -10 volts.
a. What is the magnitude of the negative charge?
b. If a positive charge of the double the magnitude of the first charge moved between the same two points in the field, determine the change in electric potential and the change in electric potential energy.
c. Would the positive charge in part b speed up or slow down?
6. Assume the central charge shown below is at rest and will remain at rest. Evaluate the scenario to answer the following questions:
a. In which direction will the test charge move?
b. Will the test charge speed up or slow down?
c. Will the kinetic energy of the particle increase or decrease?
d. Will the electric potential energy increase or decrease?
e. Will the electric potential increase or decrease?
7. (moderate) An E-field exists such that its components in the x and z directions are zero, but the component to the y direction is 6.0 N/C (uniform). A proton moves from the origin to the position y = 10.0 m. Determine the change in electric potential. Additionally, find the change in potential if the proton moved from the origin to x = 10.0 m.
8. (moderate) A charged particle moves along a straight line in a uniform E-field (E = 50 V/m). The field in in the same direction as the displacement. Find the change in electric potential if the object moves from x = 5.0 m to x = 100.0 m. Does the change in potential depend upon the positive or negative nature of the charge?
9. (moderate) A charged particle (+2.2 pC) moves along a the x axis in an E-field (22 N/m) that is also directed along the x-axis. Determine both the change in electric potential and the change in electric potential energy (in MeV) for the particle when it undergoes a displacement from x = 2 m to x = 20 m. Will this particle speed up or slow down?
Please supplement these problems with those found in your companion text.