Problem 9: The figure shows the electric field lines near two charges q1 (red, on the left) and q2 (blue, on the right).

Three equal point charges of varying signs are placed on three of the corners of a square of side d as shown in Figure. Which of the arrows shown represents the direction of the net electric field at the vacant corner of the square? d -q +0 A B D d none of the above A 8 -q D

Plastic beads can often carry a small charge and therefore can generate electric fields. Three beads are oriented such that 92 is between 9₁ and 93. The sum of the charge on 9₁ and 92 is 91 +92 = -8.3 μC, and the net charge of the system of all three beads is zero. E field lines What charge does each bead carry? μC 91 = 92 = 93 = 000 μC μC

You hold a ruler that has a charge on its tip 4.00 cm above a small piece of tissue paper to see if it can be picked up. The ruler has  −10.0 µC  of charge. The tissue has 1.00 g of mass. What is the minimum charge required to pick up the tissue paper?

Five point charges, all with q= 60 nC, are spaced equally along a semicircle as shown in  the Figure. If the semicircle has a radius of 9.5 m, what is the magnitude of the electric field at the origin?

The figure below shows a dipole. If the positive particle has a charge of 31.9 mC and the particles are 2.70 mm apart, what is the electric field at point A located 2.00 mm above the dipole's midpoint? (Express your answer in vector form.) N/C E = A d/2 y d/2 X

Consider the following. B 0.500 mm 60.0° (a) Red blood cells often become charged and can be treated as point charges. Healthy red blood cells are negatively charged, but unhealthy cells (due to the presence a bacteria, for example) can become positively charged. In the figure, three red blood cells are oriented such that they are located on the corners of an equilateral triangle. The red blood cell charges are A = 1.80 pC, B = 6.60 pC, and C = -4.40 pC. Given these charges, what would the magnitude and direction of the electric field be at cell A? magnitude N/C direction ° counterclockwise from the +x axis (b) If the charge of cell A were doubled, how would the electric field at cell A change? O The magnitude of the field would be doubled. O The field would be unchanged. O The magnitude of the field would be halved. O The magnitude of the field would be quadrupled.

A small plastic bead has a mass of 3.68 g and a charge of -16.6 µC. It levitates, motionless, when placed in a uniform electric field perpendicular to the ground. What is the magnitude of the electric field (in N/C)? N/C What is the direction of the electric field? O upward O downward O east O west

The gecko is sticking upside down to a smooth ceiling. The remarkable adhesion might be due to static electricity. Gecko feet are covered with microscopic hairs. When these hairs rub against a surface, charges separate, with the hair developing a positive charge and negative charge forming below the surface. There is an attractive force between the separated charges. This is an effective means of adhering to a surface, but it comes at a cost: Two planes of charge are like two charged plates of a capacitor, which takes energy to charge. Doubling the amount of charge on each surface increases the attractive force, but also increases the energy required to separate the charge. Part A By what factor does this energy increase? (UElec){ (UElec); ΕΧΕΙ ΑΣΦ Submit Request Answer Provide Feedback ?

A 4.1 MC point charge is placed on the x-axis at the point X₁ = -22.5m. A second, 2.7-MC point Charge is placed on the x-axis at the point X₂ = 10.3m. What is the x-component of the net electric field (in N/C) at the origin? (Remember that vector components can be positive or negative) N/C