A student places a paperclip on a table. When they hold a magnet underneath the table, the paperclip slides across the top. Why does the paperclip move?

The heat from the student's hand makes the paperclip slide away.

The table is tilted, causing the paperclip to slide down due to gravity.

The magnet creates an invisible magnetic field that pulls the paperclip, causing it to change its position.

Vibrations from the student holding the magnet cause the table to shake just enough for the paperclip to move.

If you cannot see a force, how can you be certain it exists?

By guessing based on the weather.

You can't; if a force is invisible, it is impossible to detect.

By observing its effect on an object's movement.

By measuring the object's weight before and after.

The wall is sticky and can hold light objects like balloons.

An invisible force of static electricity is pulling the balloon to the wall.

The balloon is now lighter than air, so it naturally floats up against the wall.

The air in the room is pushing the balloon against the wall with great pressure.