Question

1. the metal ball shown below (left) is neutrally charged and rests on an insulating stand. a positively charged glass rod is then brought close to the sphere (shown at right). draw the new charge distribution in the sphere.
2. a negatively charged rubber duck is brought near a neutrally charged styrofoam ball. the styrofoam ball will...

a) be attracted to the duck
b) be repelled by the duck
c) not be affected by the duck

1. in a lightning storm, charge flows between the sky and ground. you are generally safer inside a car than outside. explain why, referring to necessary charge terms (conductor, insulator, discharge) and common car materials (rubber tires, metal exterior, plastic interior).

Explanation:

1.

Step1: Identify charge polarization

A neutral conductor's free electrons are attracted to a nearby positive charge, shifting toward the rod, leaving the opposite side with a net positive charge.

Step2: Draw charge distribution

On the right metal sphere: draw a cluster of - charges on the side closest to the positively charged glass rod, and a cluster of + charges on the side farthest from the rod. The interior of the sphere has no net charge shown.

A neutral insulator (Styrofoam ball) will have charge polarization: the positive charges in its molecules shift toward the negative duck, and negative charges shift away. This creates a net attractive force between the induced positive side of the ball and the negative duck.

A car's metal exterior is a conductor. When lightning (a large discharge of charge) occurs, the charge will induce a separation of charge on the metal conductor. The charge will reside entirely on the exterior surface of the metal (Faraday cage effect), leaving the interior free of electric fields and charge flow. The rubber tires (insulators) prevent the charge from discharging into the ground through the car's interior, and the plastic interior (insulator) keeps occupants isolated from the charged exterior. This means no charge flows through the interior, so people inside are protected from the discharge.

Answer:

The metal sphere will have an excess of negative charges on the side near the positive glass rod, and an excess of positive charges on the side farthest from the rod (the interior remains essentially neutral with no net charge visible).

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2.