This learning resource is available in interactive and printable formats. The interactive worksheet can be played online and assigned to students. The Printable PDF version can be downloaded and printed for completion by hand.
This grade 6-8 science passage explores the fundamental difference between mass and weight, aligned with NGSS standard MS-PS2-4. Students learn that mass is the amount of matter in an object and remains constant, while weight is the force of gravity acting on that mass and can change depending on location (Earth, Moon, or space). The passage explains the formula weight = mass × gravity, provides real-life examples including astronauts, and addresses common misconceptions. Key vocabulary is highlighted and defined in a glossary. Activities include a multiple-choice quiz, writing prompts, and graphic organizers, designed to deepen understanding and encourage scientific reasoning. Audio supports and Spanish translations are included for accessibility. This resource is ideal for classrooms seeking standards-based, engaging, and differentiated instruction about physical science concepts.
CONTENT PREVIEW
Expand content preview
Mass remains constant while weight changes with gravity
Mass and weight are two scientific concepts often confused, but they play different roles in understanding our universe. On Earth, a bathroom scale shows a number when you step on it, but does that number represent your mass or your weight? Scientists have found that, while related, mass and weight are not the same. Understanding the difference is vital for everything from space travel to everyday measurements in science.
How Mass and Weight Work
Mass is the amount of matter—the stuff that makes up an object. It remains constant no matter where you are in the universe. Mass is measured in kilograms (kg). Weight, however, is a force. It is the pull of gravity on an object's mass. The formula for weight is: weight = mass × gravity. On Earth, gravity is about 9.8 newtons per kilogram (N/kg). So, if you have a mass of 50 kg, your weight on Earth is 50 kg × 9.8 N/kg = 490 newtons (N). In this way, weight depends on both your mass and the strength of gravity where you are.
Examples from Earth, Moon, and Space
An astronaut's mass is the same everywhere—let’s say 80 kg. On Earth, the weight is 80 kg × 9.8 N/kg = 784 N. On the Moon, gravity is much weaker, about 1.6 N/kg. The astronaut’s weight there is 80 kg × 1.6 N/kg = 128 N. In deep space, far from planets, gravity is almost zero, so weight nearly disappears, but mass stays at 80 kg. This shows that mass stays the same but weight changes depending on gravity. Everyday objects show this, too: a rock has the same mass on Earth and Mars, but its weight will be less on Mars due to weaker gravity.
Common Misconceptions and Scientific Thinking
Many people believe weight and mass are the same, partly because we often use 'weight' to mean 'how heavy' something is. However, scientists carefully separate the two ideas. For instance, astronauts must know their true mass so they can calculate fuel needs, even when their weight is much less on the Moon or in space. This distinction is important in physics, chemistry, and engineering. Knowing the difference helps us predict how objects will move, design safe vehicles, and understand forces in nature. The law of universal gravitation explains that every mass pulls on every other mass, but the strength of that pull depends on mass and distance.
Understanding mass and weight shows how physical laws connect objects, forces, and motion throughout the universe. Whether on Earth, the Moon, or beyond, this distinction is crucial for science and technology.
Interesting Fact: On Jupiter, your weight would be more than twice what it is on Earth, because Jupiter’s gravity is much stronger!
Which of the following best describes mass?
The amount of matter in an objectThe force gravity has on an objectThe weight of an object on EarthHow heavy an object feels
What is the correct formula for calculating weight?
weight = mass × gravityweight = mass + gravityweight = mass ÷ gravityweight = gravity – mass
Which unit is used to measure weight in the metric system?
KilogramMeterNewtonLiter
Why does an astronaut weigh less on the Moon than on Earth?
The astronaut’s mass is less on the MoonGravity is weaker on the MoonThe Moon has no atmosphereThe Moon is closer to the Sun
What happens to your mass if you travel from Earth to space?
It increasesIt decreasesIt stays the sameIt disappears
In the passage, which word describes a push or pull on an object?
GravityForceMassMatter
What does the law of universal gravitation state?
All objects with mass attract each otherWeight and mass are the sameGravity is the same everywhereObjects in space have no mass
If a rock weighs less on Mars than on Earth, what stays the same?
Its massThe pull of gravityIts weightIts speed
True or False: Weight changes depending on the strength of gravity.
TrueFalse
True or False: Scientists use the word 'weight' to mean 'mass' in physics.
TrueFalse
Perfect For:
👩🏫 Teachers
• Reading comprehension practice
• Auto-graded assessments
• Literacy skill development
👨👩👧👦 Parents
• Reading practice at home
• Comprehension improvement
• Educational reading time
🏠 Homeschoolers
• Reading curriculum support
• Independent reading practice
• Progress monitoring
Reading Features:
📖
Reading Passage
Engaging fiction or nonfiction text
❓
Comprehension Quiz
Auto-graded questions
📊
Instant Feedback
Immediate results and scoring
📄
Printable Version
Download for offline reading
🔊
Read Aloud
Voice-over with word highlighting
Reviews & Ratings
No reviews yet. Be the first to share your experience!
Related Content
Gravity
This comprehensive science passage introduces middle school students to the concept of gravity, the invisible force that...
MS-PS2-4
Scientific Laws
This comprehensive middle school science passage introduces students to scientific laws, focusing on how they describe c...
MS-PS2-4MS-PS1-5MS-ETS1-4
What Is Gravity?
This comprehensive middle school science reading passage explores the concept of gravity, aligning with NGSS standards M...
MS-ESS1-2MS-PS2-4
Weight vs. Mass
This passage explains the essential scientific concepts of weight and mass for middle school students. It addresses comm...
MS-PS2-4
Escape Velocity and Space Travel
This middle school science passage introduces students to the concept of escape velocity—the minimum speed required to b...
MS-ESS1-2MS-PS2-4
Weightlessness and Microgravity
This science reading passage for middle school students explores the phenomenon of weightlessness and microgravity. Alig...
MS-PS2-4MS-ESS1-2
Orbits and Orbital Motion
This middle school science passage, aligned with NGSS MS-ESS1-2 and MS-PS2-4, explores the science of orbits and orbital...