For the first question, the answers look correct. The equation for electric force F depends on an electric field's strength E and the charge of the particle that the force acts on q.
F = Eq
(If the electric field E is caused by another particle with charge Q, then this would be (E = kQ/r^2)
F = kQq/r^2)
The answer to the second question is probably that the charged rod "induces" a the charges in the metal can to polarize, which sometimes happens in conductors when a charge is near. Basically, this means that the electrons in the metal can flow toward the side of the can that is near the rod.
This is explained in this video:
At around 7:50 in the video, charge by electrical induction is explained.
Blessed enough to go to school
· 4 weeks ago