Base your answers to questions on the information below and on your knowledge of science.
Forces That Act Without Touching
In Investigation 1, students placed a magnet different distances above a pile of steel paper clips. They counted how many paper clips the magnet lifted without touching them.
In Investigation 2, students rubbed a balloon on a wool sweater a different number of times. Then they slowly lowered the balloon toward small bits of tissue paper and measured how far away the balloon was when the paper first jumped up to it.
A cabinet company wants a magnetic latch that holds a door shut. The latch must hold at least 5 paper clips’ worth of pull so the door stays closed, but it should be as easy as possible to open.
The magnet is held still above the paper clips. It never touches them. Only the distance is changed.
Distance between magnet and paper clips
Rubbing the balloon on wool gives it a static electric charge. The balloon is lowered until a piece of tissue paper first jumps up toward it.
| Times Rubbed on Wool | Distance When Paper Jumped (cm) |
|---|---|
| 0 | Paper did not jump |
| 5 | 2 |
| 10 | 4 |
| 20 | 6 |