List of Topics

SfC Home > Physics > Gravity >


Mini-Quiz: Convention for Direction in Gravity Equations

by Ron Kurtus (revised 15 March 2011)

Take this Mini-Quiz to check your understanding of the lesson material.

1. Why isn't "up" considered positive as it is in the x-y coordinate system?

There is no such thing as upward or downward in the x-y coordinate system

Since the force of gravity is downward, it is more logical to have that direction as positive for gravity studies

Many people have wondered about that convention

2. From where is the displacement of a projected object measured?

Displacement is measured from the starting point

Displacement is always measured from the ground

Displacement varies according to distance traveled

3. If a ball is thrown upward, what sign is its velocity on the way down?

It is negative, since it started going upward

It is positive, since it is moving toward the ground

It depends whether the displacement is positive or negative

If you got all three correct, you are on your way to becoming a Champion in Physics. If you had problems, you had better look over the material again.

Realize that you have hidden skills

Resources and references

Ron Kurtus' Credentials


Vectors and Direction - Physics Classroom

Gravity Resources


Top-rated books on Simple Gravity Science

Top-rated books on Advanced Gravity Physics

Questions and comments

Do you have any questions, comments, or opinions on this subject? If so, send an email with your feedback. I will try to get back to you as soon as possible.


Click on a button to bookmark or share this page through Twitter, Facebook, email, or other services:


Students and researchers

The Web address of this page is:

Please include it as a link on your website or as a reference in your report, document, or thesis.

Copyright © Restrictions

Where are you now?

School for Champions

Gravity topics

Mini-Quiz: Convention for Direction in Gravity Equations

Gravity and Gravitation

Gravity topics


Derivations of equations

Falling objects

Projected downward

Projected upward

Gravity and energy

Gravity and work

Gravity applications


Let's make the world a better place

Be the best that you can be.

Use your knowledge and skills to help others succeed.

Don't be wasteful; protect our environment.

You CAN influence the world.

The School for Champions helps you become the type of person who can be called a Champion.