Forces and Structures

What is torsion?

• a twisting or turning force
• a force that makes a straight material become curved
• a pushing force that squeezes
• a pulling force that stretches a material

What is compression?

• a twisting or turning force
• a force that makes a straight material become curved
• a pulling force that stretches a material
• a pushing force that squeezes a material 

What is bending?

• a twisting or turning force
• a force that makes a straight material become curved
• a pulling force that stretches a material
• a pushing force that squeezes a material 

What is tension?

• a twisting or turning force
• a force that makes a straight material become curved
• a pulling force that stretches a material
• a pushing force that squeezes a material 

Which of these describes a beam bridge?

• Has tall towers that support a main cable
  
• Built with triangles made of steel bars.
• A curve shaped bridge.
• Has a horizontal beam supported by piers

Which of these describes a truss bridge?

• An curve shaped bridge
• Built with triangles made of steel bars
• Has tall towers which support a main cable.
• Has a horizontal beam supported by piers

Which of these describes an arch bridge?

• An curve shaped bridge
• Has tall towers which support a main cable.
• Has a horizontal beam supported by piers
• Built with triangles made of steel bars

What is an internal force?

• A force that acts outside a structure
• an x-ray force
• A force that acts from within the structure

What is an external force?

• A force that acts from within the structure
• A force that acts outside a structure
• an x-ray force

Wind is what kind of force?

• a  big force
• internal force
• external force
• a wind force