1. Last year some grade 7 students built popsicle-stick bridges. The bridge had a mass of 103g and was able to carry 28.4kg (28,400g). What was its structural efficiency? (You need to round the number up)

• 301

• 245

• 10

• 276

What two specific things does structural efficiency compare?

• mass of structure and length of structure

• mass of structure with the mass of the load it can support

• mass of structure and height of structure

• mass of structure and weight of structure

Tags

NGSS.MS-PS2-2

Fred used 300g of materials to build a model bridge that supported and 8.0 kg load. Sally's bridge had a mass of 175 g and supported a load of 5kg. Who won the prize for most efficient structure.

• Fred

• Sally

Tags

NGSS.MS-ETS1-2

NGSS.MS-ETS1-3

A table weighing 30kg was able to support 90,000g. What is the structural efficiency of the table.

• 3

• 4

• 2

• 5

A tower built of straws was able to support 6 grams. The tower itself weighed 20 grams. What is the structural efficiency?

• .75

• 1

• .3

• 1.3

A beetle can support 798 times its own weight. What is the structural efficiency of the beetle?

• 45

• 278

• 141

• 798

Tags

NGSS.MS-ETS1-1

During Henry's birthday party, people placed their gifts on a table. During the party the table collapsed due to the mass of all the gifts. If the mass of the gifts was 540 kg, and the table had a mass of 60 kg, what was the structural efficiency of the table?

• 9

• 4

• 7

• 10

Tags

NGSS.MS-PS2-2

Knowing an ant has a mass of 0.003g (3 milligrams), and can lift 30 times its own mass. What is the maximum mass the ant can support.

• .4 g

• 120 milligrams

• 90 milligrams

• .08 g

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

What makes a strong and stable structure?

• wide base
• triangles
• decreasing perimeter
• all of these

Tags

NGSS.MS-ETS1-3

NGSS.MS-ETS1-4

What is the force that squeezes materials together?

• compression
• tension
• shear
• torsion^