Question

It is Friday night and Dr. J's classroom is full of eager young students. Yes, it's the weekly meeting of the Wizards of Oz, a club for bright preteens interested in science. This particular night is even more special because new members will be officially received into the club. Dr. J had been attracted to the group over a year ago and, after rubbing shoulders with the youngsters, his interest was sparked. His attitude grew more positive over the following months when he saw the tremendous potential associated with their capacity to learn. Being charged with the responsibility of this induction ceremony, Dr. J has decided to use electrostatics as the theme of the evening. Each student is given an experiment to run in order to demonstrate the skills necessary for membership. Having left his patches of wool at home by mistake, Dr. J instructs everyone to use Tripod as their charge cloth. The fur only flies once as Tripod is rubbed the wrong way. (He takes a negative view of his role.) Perhaps the toughest experiment is the one given to the incoming president. Having been told to weigh the pros and cons of pith balls, he has charged two of them equally. They are 3 cm apart and are repelling each other with a force of 4 x 10-5 N. What is the weight of the excess electrons on one of the balls?

2. Which is more dangerous, touching a faulty 110-volt light bulb or a Van de Graaff generator charged to 100,000 volts? Why? Give a detailed elaborate answer.

3. Calculate the size of the force that would be experienced by a 3.0 µC charge placed into a uniform electric field of strength 1.0 x 10⁵ N/C.

4. A – 5.0 mC charge travels due south under the influence of a 10 N force when placed into a uniform electric field. What force would a 10 mC charge experience if placed in the same field and in which direction would it move?

5. What is the magnitude of a point charge that would create an electric field of 1.00 N/C at points 1.00 m away?

6. Consider a fixed point charge of +2.00 μC. What is the magnitude and direction of the electric field at a point P, a distance of 0.100 m away?

7. An electric field has an electric field strength 6000. N/C at a distance of 1.5 m. What is the strength of the field at a distance of 6.0 m?

8. 24. An alpha (α) particle is positioned in an electric field such that the gravitational force acting on it is equal to the electrostatic force.

             (q_α = 3.2 x 10^–19 C and m_α = 6.64 x 10^–27 kg)

a) What is the direction of the electric field at this point?

b) What is strength of the electric field?

c) If the field is located 0.25 m away, what is the magnitude of the charge?

9. Determine the potential at a point 0.50 m from a 20. µC point charge.

10. An electric field is parallel to the x-axis. What is the magnitude and direction of the electric field if the potential difference between x = 1.0 m and x = 2.5 m is found to be +900 V?

11. A charged droplet of mass 5.88 x 10^–10 kg is hovering motionless between two parallel plates. The parallel plates create have a potential difference of 24000 V and are 2.00 mm apart. What is the charge on the particle?

Answer 1