# PH.10 - Gravitational, Electric, and Magnetic Forces

The student will investigate and understand how to use the field concept to describe the effects of gravitational, electric, and magnetic forces. Key concepts include

a)  inverse square laws (Newton’s law of universal gravitation and Coulomb’s law); and

b) technological applications.

Bloom's Levels:  Analyze; Understand

### BIG IDEAS

• I can explain how generators work.
• I can explain how electricity helps a recycling center sort metals.

### UNDERSTANDING THE STANDARD

The concepts developed in this standard include the following:

• The electrostatic force (Coulomb’s law) can be either repulsive or attractive, depending on the sign of the charges.
• The gravitational force (Newton’s Law of Gravitation) is always an attractive force.
• The force found from Newton’s Law of Gravitation and in Coulomb’s law is dependent on the inverse square of the distance between two objects.
• The interaction of two particles at a distance can be described as a two-step process that occur simultaneously: the creation of a field by one of the particles and the interaction of the field with the second particle.
• The force a magnetic field exerts on a moving electrical charge has a direction perpendicular to both the velocity and field directions. Its magnitude is dependent on the velocity of the charge, the magnitude of the charge, and the strength of the magnetic field.

### ESSENTIALS

In order to meet this standard, it is expected that students will

a)  describe the attractive or repulsive forces between objects relative to their forces and distance between them (Coulomb’s law).

describe the attraction of particles (Newton’s Law of Universal Gravitation).

describe the effect of a uniform magnetic field on a moving electrical charge.

### KEY VOCABULARY

Updated: May 09, 2018