# Understanding Gravity

by Ron Kurtus (updated 16 March 2023)

** Gravity** is the force that pulls objects toward the Earth. It is an approximation of Gravitation, which is the force that attracts matter and all objects toward each other.

Gravity is a subject in Physics, which in turn is a branch of Physical Science. There is a great need for people who understand scientific principles and know how to think logically. Your knowledge and skills in these areas can help you excel in school, advance your career or improve your business.

The purpose of these free online lessons is to give you a start at improving your scientific knowledge of Gravity that will help you become a champion in the field.

## Gravity Contents

## Overview

## Basics

Convention for Direction in Gravity Equations

Equivalence Principle of Gravity

Confusion about Mass and Weight Units

## Derivations of equations

Overview of Gravity Equation Derivations

Derivation of Velocity-Time Gravity Equations

Derivation of Displacement-Time Gravity Equations

## Falling objects

Overview of Gravity Equations for Falling Objects

Velocity Equations for Falling Objects

Displacement Equations for Falling Objects

## Projected downward

Overview of Gravity Equations for Objects Projected Downward

Velocity Equations for Objects Projected Downward

Displacement Equations for Objects Projected Downward

## Projected upward

Overview of Gravity Equations for Objects Projected Upward

Velocity Equations for Objects Projected Upward

Displacement Equations for Objects Projected Upward

## Gravity and energy

Overview of Energy from Gravity

Energy of Objects Projected Downward

## Gravity and work

Work by Gravity Against Inertia and Air

## Gravity applications

Effect of Gravity on Sideways Motion

Effect of Gravity on an Artillery Projectile

Effect of Gravity on a Rocket Projectile