Grade 3 Structures
What is the name of the person who designs a structure?
What is it called when you use a triangle shape to make a structure stronger and more stable?
Triangulation
Which type of pulley has a wheel that can move? A moveable pulley, a fixed pulley, a floating pulley, or a winding pulley?
A moveable pulley has a wheel that can move. A fixed pulley has a wheel in a fixed location. What are floating and winding pulleys? We haven't learned about those!
What is movement that occurs in a straight line called?
Linear motion
What is a force where something is squished down or pushed together?
Compression
What is a force where something is pulled apart or stretched?
Tension
What is a measure of rotational force called?
Torque
What is movement in a circular path called?
Rotary Motion
What is the name of a rod or bar that helps a structure resist pressure? A tent pole is this.
A strut.
What is the name of a beam or wire that supports a structure with tension? A tent cord is this.
A tie
What is made up of two or more simple machines?
A complex machine.
What is a basic tool that helps apply force and do work?
A simple machine
List 3 Natural Structures
-Nest
-Shell
-Bee hive
-Tree
-Beaver dam
List 3 Built Structures
-House
-Fence
-Ladder
-Cabin
-Bridge
List 3 examples of things with a pulley mechanism.
-Crane
-Well
-Elevator
-Blinds
-Flagpole
List 3 examples of things with a gear mechanism.
-Car
-Clock
-Bicycle
-Drill
-Guitar
Why are structures important to humans?
-Give us a safe place to play, live, and work
-Structures, like cranes, can help us build other structures
What is the definition of a structure?
A structure is something with a definite size, shape, purpose, and can hold a load.
If the first gear has more teeth than the second, will the second gear turn slower or faster?
The second gear will turn faster, but with less force.
If the second gear has more teeth, will it increase or decrease the amount of force?
Increase. The second gear will turn slower, but with more force.