01 vectors and electric field (seatwork part)

Seatwork:1. Find the electric potential at (3.0m,3.0m) due to a point charge q =

-2.0 C located at (-3.0m,3.0m)

2. Find the electric potential at (-3.0m,-1.0m) due to three point charges: q1 = 2.0 C at (1.0m,0) q2 = -1.0 C at (0,0) q3 = -0.10 C at (-3.1m,-1.1m)

3. A charge q = 1.0 C is placed at the origin. Find the electric potential at

a. (1.0m,0 m)b. (0,1.0m)c. (0,-1.0m)d. (-1.0m,0)e. What do you notice in your answers from 3a to 3d.

Seatwork:4. From #3, draw a line connecting points with a potential of

a. V = 9.0 x 109 Voltsb. V = 5.0 x 109 Voltsc. V = 1.0 x 109 Voltsd. What can you conclude about the shape of the line?

5. A spherical balloon contains a positive charge at its center. As the balloon is inflated to a greater volume, the electric potential on the surface

a. increaseb. decreasec. remains the same

6. Intuition Test. A positive charge is under the influence of an electric potential. The charge will tend to

a. go to regions of lower potentialb. go to regions of higher potentialc. stay in its original position

Seatwork:7. Two points A and B are located within a region in which there is an

electric field. The potential difference ΔV = VB - VA is a. positiveb. negativec. zero

8. A negative charge is placed at A and moved to B. The change in potential energy of the charge-field system is

a. positiveb. negativec. zero

Seatwork:9. At a certain distance from a point charge, the magnitude of the

electric field is 500 V/m and the electric potential is 3.00kV.a. What is the distance to the charge?b. What is the magnitude of the charge?

10. Three charges are at the vertices of an isosceles triangle. Calculate the electric potential at the midpoint of the base with q = 7.00 µC.

11. Show that the amount of work required to assemble four identical point charges of magnitude Q at the corners of a square of side s is 5.41kQ2/s.

Seatwork:

12. A particle with a charge of +4.20 nC is in a uniform electric field→E

directed to the left. It is released from rest and moves to the left; after is hasmoved 6.00 cm, its kinetic energy is found to be +1.50× 10−6 J.(a) What work was done by the electric force?(b) What is the potential of the starting point with respect to the end point?

(c) What is the magnitude of→E?

Recall the formula for the conservation of energy:12mv2i + Ui =

12mv2f + Uf