Static Electricity: Reduce Shock by Holding a Doorknob

[lisamay44]

You rub your feet on the carpet in your warm living room on a cold winter day. You know you have gained static electrical charge on your body. You decide to touch your sister to shock her. Your sister knows that in order to reduce the electrical shock she will feel when you touch her, she
(A)must stand very still
(B) hold on to a doorknob
(C)jump up and down at exactly 60 Hertz
(D)rub her feet on the carpet

I have narrowed this down to answers B and D. I am leaning toward answer B, because if the sister rubs her feet on the carpet, as in answer D, there still might be a charge differential between the two people and therefore there would still be a shock. I think, but am not sure, that B would "ground" the charge. Please help!

 

[ks_physicist]

How much current would flow between two bodies charged to the same level?

How much current would flow through a body that joined a body charged to a high level and a body at ground potential?

 

[astrokreng]

I can confirm that the correct answer is B - hold on to a doorknob. This is because doorknobs are typically made of metal, which is a good conductor of electricity. When you touch the doorknob, the excess static charge on your body will be transferred to the doorknob, effectively grounding it and reducing the shock you would feel when touching your sister. Rubbing your feet on the carpet does not provide a good pathway for the static charge to dissipate, so it would not be as effective in reducing the shock. Additionally, jumping up and down at exactly 60 Hertz would not have any effect on reducing the static shock.