Static electricity and sparks

Question 1

Jenna rubs a PVC pipe with a wool sweater, giving the pipe a negative charge. Malik rubs a glass rod with silk, giving the rod a positive charge. They first bring the pipe close to the rod, and then hold a small neutral aluminum can near each charged object. Which statement correctly describes what happens?

Accepted Answer

The pipe and the rod pull toward each other, and the can is attracted to both the pipe and the rod.

Answer

The pipe and the rod push each other away, and the can is attracted only to the rod.

Answer

The pipe and the rod push each other away, and the can is attracted to both the pipe and the rod.

Answer

The pipe and the rod pull toward each other, and the can is attracted only to the pipe.

Question 2

Sam rubs a rubber balloon on his cotton T‑shirt and then presses the balloon against a wall, and the balloon sticks. Which statement correctly explains what happened during the rubbing?

Accepted Answer

Electrons moved from the shirt to the balloon, giving the balloon a negative charge and the shirt a positive charge.

Answer

Electrons moved from the balloon to the shirt, giving the balloon a positive charge and the shirt a negative charge.

Answer

Protons moved from the shirt to the balloon, giving the balloon a positive charge.

Answer

No charge was transferred; the balloon sticks because the balloon and wall are the same material.

Question 3

When a glass rod is rubbed with a piece of silk, the glass rod becomes positively charged and the silk becomes negatively charged. Which statement best explains why this happens?

Accepted Answer

Rubbing transfers electrons from the glass to the silk; the glass loses electrons and becomes positive, while the silk gains electrons and becomes negative.

Answer

Rubbing adds extra electrons to both the glass and the silk, so both objects become negatively charged.

Answer

Electrons move from the silk to the glass during rubbing, making the glass negative and the silk positive.

Answer

The friction creates a new kind of charge that makes the glass positive and the silk negative without moving any electrons.

Try three questions

Sam rubs a rubber balloon on his cotton T‑shirt and then presses the balloon against a wall, and the balloon sticks. Which statement correctly explains what happened during the rubbing?

When a glass rod is rubbed with a piece of silk, the glass rod becomes positively charged and the silk becomes negatively charged. Which statement best explains why this happens?

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