Assignment Chapter 3

1. If glass and paraffin wax are rubbed, what charge develops on each? (1 mark)

2. The force between two charged objects is -4.3 X 10^-3 N. The charge on one object is

doubled, the other charge is reduced to one third its original value, and the distance between

the objects is halved. What is the new force between the objects? (3 marks)

3. What is the force between two charges of 3.8 X 10^-5 C and 2.7 X 10^-4 C if they are 3.74 cm

apart? (2 marks)

4. For the diagram below, calculate the force on object A as a result of objects B and C. Use the

coordinate system shown to make your calculations. (6 marks)

5. Three charges are lined up as in the diagram. A has a charge of +2.8 X 10^-5 C, B has a

charge of -3.6 X 10^-6 C, and C has a charge of +9.3 X 10^-5 C. What is the force on A due

to the other two charges? (3 marks)

6. What is the electric field intensity 0.38 m away from a small sphere with a charge of

-2.7 X 10^-9 C? (2 marks)

7. A charge of -3.7 X 10^-10 C has a force of 4.82 N applied to it. What is the strength of the

electric field which is responsible for transmitting this force? (2 marks)

8. How much force must be applied to move an object with charge 1.3 X 10^-5 C, between two

points separated by a distance of 1.8 m, when a potential difference of 93.6 V exists between

the points? (2 marks)

9. A charge when placed in an electric field with magnitude 1.83 X 10³ N/C, has a force of

-14.3 N applied to it. If this charge is removed from the electric field, what would be the

electric potential at a distance of 0.65 m from the charge? (4 marks)

10. A latex sphere of mass 1.830 X 10^-14 kg remains stationary between two parallel plates with

a potential difference of 521.0 V between them. If the plates are separated by a distance of

2.920 cm, what is the charge on the latex sphere? (4 marks)

11. An object has an excess of 4.3 X 10⁸ electrons. Calculate the electric field intensity and

electric potential at a distance of 0.38m from the object. (3 marks)

12. Object A with a mass of 1.4 X 10^-3 kg has a charge of 3.8 X 10^-10 C. This object is at

rest a distance of 48 cm from a fixed object B of charge 4.2 X 10^-5 C. The two objects will

repel each other. With what speed will object A be moving at when it is 96 cm from object B?

(4 marks)

13. Two charged objects A and B have masses of 1.3 X 10^-2 kg and 2.6 X 10^-2 kg respectively.

Their charges are -1.7 X 10^-4 C and -3.8 X 10^-4 C respectively. They are released from

rest when they are 3.6 m apart. What will their speeds be when they are a "large'' distance

apart? (6 marks)

December 30, 2013