Load Lab Vocabulary Guide
Middle School Science & Engineering
LOAD LAB VOCABULARY GUIDE
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Unit 1 • Mechanical Forces & Stresses
5 Terms • Grades 6–8 Physics
OBJECT Push Pull
Forces
Noun • Science
A push or a pull on an object. Forces can make things start moving, speed up, slow down, stop, or change shape. Scientists measure forces in Newtons (N).
Example: Gravity pulling downward and heavy winds pushing sideways are forces that act on bridges.
Tension
Tensile Force
A pulling or stretching force that tries to make an object longer. Think of playing tug-of-war or stretching a rubber band until it is tight.
PULL / STRETCH
Kid Example: The cables on a suspension bridge are pulled in tension.
Compression
Compressive Force
A pushing or squeezing force that presses inward on an object. Think of squishing a marshmallow or sitting on a foam cushion.
SQUEEZE / PUSH
Kid Example: Giant concrete bridge pillars are squeezed in compression.
Shear
Sliding Force
Forces that push in opposite directions across from each other, causing parts to slide or tear sideways. Think of scissors cutting paper.
Sliding Planes
Kid Example: Bolts holding metal beams together must resist being snapped by shear.
Torsion
Twisting Force
A twisting force created when one end turns one way and the other end stays still or turns the other way. Think of wringing water out of a wet towel.
TWISTING FORCE
Kid Example: Powerful swirling winds can twist a long bridge deck back and forth.
Pro Tip
Forces work together! When a heavy truck drives onto a bridge beam, the top of the beam gets squeezed by compression while the bottom gets pulled by tension at the same time.
Middle School Engineering Guide • Grades 6–8 Section 1 of 4 • Mechanical Forces Page 1
Middle School Science & Engineering
LOAD LAB VOCABULARY GUIDE
Bridge & Building Parts
Unit 2 • Structural Elements & Types of Loads
6 Terms • Structures & Loads
Load
Total Weight
The total weight or force pushing down or against a structure. It includes the materials of the structure, everything on it, and weather forces.
LOAD (Weight) Supported Span
Example: Engineers must calculate how much load a roof can hold before it collapses.
Dead Load
Permanent Weight
The permanent weight of the structure itself that never moves. This includes the heavy concrete, steel beams, nails, and road surface.
DECK & STEEL BEAMS Self-Weight Never Moves
Example: A bridge has to support its own massive dead load even when empty.
Live Load
Moving Weight
The temporary or moving weight placed on a structure that changes over time, like driving cars, walking people, furniture, wind, and snow.
Wind & Cars
Example: School buses stuck in traffic during rush hour create a heavy live load.
Beam
Horizontal Bar
A sturdy, horizontal bar or plank supported at its ends that carries weight across an open space without snapping or bending too much.
Center Load Beam Bending Slightly
Example: Thick wooden beams run beneath the floor of a house to keep it level.
Truss
Triangle Frame
A super-strong framework made of straight pieces joined into triangles. Triangles are used because they are rigid and cannot easily be squashed.
Strong Triangle Network
Example: Railroad bridges use trusses so heavy freight trains can cross safely.
Suspension
Hanging System
A bridge design where the roadway hangs from vertical wires attached to giant curving cables strung high between tall towers.
Cables Hang the Roadway
Example: The Golden Gate Bridge uses suspension cables to span wide, deep water.
Middle School Engineering Guide • Grades 6–8 Section 2 of 4 • Elements & Loads Page 2
Middle School Science & Engineering
LOAD LAB VOCABULARY GUIDE
Science Practices
Unit 3 • Models, Systems & Design Cycles
5 Terms • Grades 6–8 Inquiry
Model
Tool / Object
A smaller copy, drawing, or computer simulation of an object or system. It lets you test how the real thing will act without building it full size first.
Scale Test Model
Example: Students built a popsicle-stick model bridge to test where it broke.
Represent
Action Verb
To stand for or show something using a symbol, picture, label, or diagram. In science, an arrow often represents the direction a force pushes.
Real Bridge Draw As Force Arrow
Example: We used red arrows to represent downward gravity pushing on the road.
Develop
Action Verb
To plan, create, test, and improve an idea or invention step by step until it solves the problem and works reliably.
IDEA BUILD 1 IMPROVED Step-by-Step Improvement
Example: Our team developed three different tower designs before building the best one.
Cycle
Repeating Loop
A series of steps that repeats in a continuous loop. What you learn at the end helps you start over and make things better next time.
REPEAT Plan Build Test Fix
Example: The engineering design cycle (Plan, Build, Test, Improve) repeats until it works!
Interact
Action Verb
To act upon or affect each other when two or more parts, objects, or forces touch, connect, or work together in a system.
Part A Part B Affecting Each Other
Example: When wind pushes on a bridge, the air and cables interact and create vibrations.
Putting It Together
How Science Words Connect
When engineers develop a new bridge, they first make a model to represent the real-life structure. As different forces interact with it, testing data feeds into a learning cycle to make the next design even stronger!
Question: If you change one part of a bridge model, how does it change how the other parts interact?
Middle School Engineering Guide • Grades 6–8 Section 3 of 4 • Inquiry & Modeling Page 3
Middle School Science & Engineering
LOAD LAB VOCABULARY GUIDE
Thinking Like a Scientist
Unit 4 • Analysis, Discussion & Making Claims
5 Terms • Grades 6–8 Critical Thinking
Analyze
Action Verb
To break down a structure, test, or data set into smaller parts to see how each part works and find where problems might happen.
Whole Top Bar Diagonal Joint
Example: We analyzed our test data to see exactly which stick snapped first.
Evaluate
Action Verb
To judge how successful something is by comparing it against your design rules, safety requirements, strength, and budget.
STRENGTH COST/WEIGHT Weighing Good & Bad
Example: Students evaluated two bridge builds to see which held more weight for less cost.
Discuss
Action Verb
To talk through ideas with your team, sharing what you noticed, listening to teammates, and working together to agree on solutions.
Example: Group members discussed their lab results before redesigning the bridge deck.
Describe
Action Verb
To tell or write clearly what you see, measure, or notice during a test using facts, numbers, and observations without guessing.
Example: Students described how the beam sagged 3 centimeters under five books.
Relationship
Connection
The connection between two things, showing how changing one variable causes the other variable to increase, decrease, or change too.
Weight Added → Bending
Example: There is a direct relationship: more weight on the beam causes more bending!
Student Quick Check
Use your new vocabulary to answer this bridge challenge:
Challenge: During a snowstorm, you need to analyze a bridge.
1. What kind of load is moving traffic and snow? [ Live Load ]
2. What twisting force happens when wind gusts hit the deck? [ Torsion ]
3. Which bridge type hangs the road from giant cables? [ Suspension ]
21 Terms Mastered Middle School Ready
Middle School Engineering Guide • Grades 6–8 Section 4 of 4 • Analysis & Reasoning Page 4
