Forces Acting at a Distance and Electromagnetism

These flashcards cover key concepts related to forces acting at a distance, electromagnetism, and gravitational attraction, extracted from lecture notes.

What are the three types of forces that act at a distance?

Magnetic, electrical, and gravitational.

What happens to magnetic field lines that come together?

They attract.

What happens to magnetic field lines that push apart?

They repel.

What are the three ways to increase the strength of an electromagnet?

1. Increase the number of wraps of wire. 2. Add more to the iron core or thicken it. 3. Increase the voltage of the battery.

In an electromagnet, where is the north pole located?

Near the positive end of the battery.

What is the function of Earth's liquid outer core?

It swirls around the solid iron core, creating a magnetic field that shields us from harmful solar winds.

How does gravitational attraction depend on mass and distance?

Gravitational attraction increases with greater mass and closer distance.

What is an outcome of a magnetic pole reversal?

A compass needle points mostly in the direction of the geographic south pole after the reversal.

What is the significant effect of Earth's magnetic field on a compass needle?

It allows the compass needle to detect the direction of Earth's magnetic North Pole.

What is the relationship between gravitational attraction and the distance between objects?

Objects that are closer together experience greater gravitational attraction.