1. When two spheres repel each other, what are the charges of these two spheres?

(a) both positive (b) different charges (c) alike (d) both negative

( e.g. "a" )

 

2. How will the force between two spheres change if the distance between two sphere doubles?

(a) double (b) one half (c) quatriple (d) one forth (e) same

( e.g. "a" )

 

3. There are two balls. Ball A has a charge of +1.8 * 10^-8 C and Ball B has a charge of
+1.5 * 10^-8 C and is 0.002 m away from A.

a. What is the force acting on A?

( e.g. "0.10 N" )

 

b.Do they attract or repel each other?

( e.g. "attract" or "repel")

4. Charged spheres A and B are fixed in position, as shown, and have charges of +7.9 * 10^-6 C and -2.3 * 10^-6 C, respectively. Calculate the net force on sphere C, whose charge is +5.8 * 10^-6 C.

( e.g. "1.00 N L" (L = left and R = right))

 

5. Three identically charged spheres A, B, and C, each with a charge of +3.0 * 10^-7 C, are located at the corners of a triangle whose sides are 30 cm long and all the angles are 60 deg. What is the net force acting on sphere A?

( e.g. "1.0*10^-1" ) N upward

 

6. What is the mass of sphere X whose charge is +1.70 * 10^-7 C and the distance between charged bar is 20 cm? The bar has a charge of +2.30 * 10^-6 C.

( e.g. "1.00*10^-1" ) kg