12. A plastic ruler is rubbed on a cotton shirt. The ruler gains a positive charge. Which of the following statements is true?
A. Protons jumped ON TO the ruler from the shirt.
B. Protons jumped OFF OF the ruler and on to the shirt.
C. Electrons jumped ON TO the ruler from the shirt.
D. Electrons jumped OFF OF the ruler and on to the shirt.

fgravity=10x10=100n case 1

fgravity=30x20=600n case 2

6 times more

i think the answer is a and b

i wish you luck

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j