Iona Prep Physics Problems from the textbook

Chapter 20:

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# 43 A strong lightning bolt transfers about 25 C to earth. How many electrons are transferred?

# 48 A positive charge of 3.0 x10^-6 C is pulled on by two negative charges. The first charge is -2.0 x10^-6 C and is 0.050 m to the left and the other is -4 x10^-6 C and is located 0.030 m to the left. What is the total force (magnitude and direction) on the positive charge?

# 49 Consider two positively charged spheres, one with three times the charge of the other. They are located 16 cm apart. The force etween them is 0.28 N. What are the charges on each of the two spheres.

# 54 A small sphere of charge 2.4 x10^-6 C experiences a force of 0.36 N when a second sphere of unknown charge is placed 5.5 cm from it. What is the magnitude of the charge on the second sphere?

# 55 Two identially charged spheres placed 12 cm apart have an electric force of 0.28 N between them. What is the charge of each sphere?

#57 The force between a proton and an electron is 3.5 x10^-10 N. What is the distance between them?

Chapter 21

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2. A negative charge of 2.0 x10^-6 C experiences a force of 0.060 N to the right in an electric field. What are the field's magnitude and direction at that location?

3. A pith ball weighing 2.1 x10^-3 N is placed in a downward electric field of 6.5x10^4 N/C. What charge (magnitude and sign) must be placed on the pith ball so that the electric force acting on it will suspend it agains the force of gravity?

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19. When a potential difference of 125 V is applied to two parallel places, the field between them is 4.25 x10^3 N/C. How far apart are the plates?

20. A potential difference of 275 V is applied to two parallel plates taht are 0.35 cm apart. What is the electric field between the plates?

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#66 What charge exists on a test charge that experiences a force of 1.4x10^-8 N at a point where the electric field intensity is 5.0 x10^-4 N/C?

#69 The electric field in the atmosphere is about 150 N/C downward. (A) What is the direction of the force on a negatively charged particle? (B) Find the electric force on an electron in the field (C) Compare the force in B with the force of gravity on the same electron (mass = 9.1x10^-31 kg).

#77 How much work is done to transfer 0.15 C through an electric potential difference of 9.0 volts?