By Myrl Shireman
Mass and
Weight
By Myrl Shireman
Illustrated By John E. Kaufmann
Copyright © 2012 Revised, Mark Twain Media, Inc.
ISBN 978-1-58037-911-3
Printing No. D04117-EB
Mark Twain Media, Inc., Publishers
Distributed by Carson-Dellosa Publishing LLC
P.O. Box 35665 • Greensboro, NC 27425
www.carsondellosa.com
Reading Level 4 (Science Facts not leveled)
Fountas and Pinnell: Level T
Interest Level: Gr. 3–7
All rights reserved. Printed in the United States of America.
D04117-EB © Mark Twain Media, Inc., Publishers
Mass and Weight
Table of Contents
Mass....................................................................................... 4
Weight.................................................................................... 9
Gravity................................................................................. 12
The Planets........................................................................... 14
Newtons............................................................................... 17
Glossary............................................................................... 19
Reading Activities................................................................ 20
Index.................................................................................... 22
D04117-EB © Mark Twain Media, Inc., Publishers
M
Mass
any people think that mass and weight are the same.
They are not. Mass is the amount of matter in an
object. The weight of an object is a result of gravity. The
mass of an object does not change. The mass of a brick
would not be changed by taking it from the earth to the
moon. The mass and shape of the brick remain the same.
However, the force of gravity is greater on Earth than on the
moon. The mass of the brick would not change on the moon,
but the weight of the brick would be much less on the moon.
Gravity affects weight. It does not affect mass.
A brick and a wooden block both have the same
length, width, and height. The mass of a brick is much
greater than the mass of a wooden block, because the brick
has more matter packed into it than the wooden block does.
They are both the same shape. However, the brick weighs
more on Earth and on the moon. It has more mass.
Weight of brick on Earth
D04117-EB © Mark Twain Media, Inc., Publishers
Weight of brick on the moon
The force of gravity affects weight.
An object will weigh six times more on Earth than
on the moon. If an object weighs ten pounds on the moon,
it will weigh 60 pounds on Earth. This is because the force
of gravity is greater on Earth than on the moon. Earth is
much larger and has a much greater mass than the moon.
Therefore, the force of gravity on Earth is much greater than
on the moon. The masses of the Earth and the other planets
in our solar system are not the same. An object would not
weigh the same on the other planets as it does on Earth.
D04117-EB © Mark Twain Media, Inc., Publishers
What would it be like to play baseball on the moon?
It would not be like playing on Earth. The mass and the
shape of the ball would be the same. The shape and the
mass of the bat would be the same. It is the weight that
changes. The weight of the bat and ball would be less on
the moon. Their weight is less because of gravity. It is
much less on the moon. Balls, bats, and players would not
weigh nearly as much on the moon.
D04117-EB © Mark Twain Media, Inc., Publishers