Mr. Sucena Lesson Outline

__________ data uses words to describe what is observed.

Qualitative

The simplest type of bridge, called a(n) ______, has one horizontal beam across two supports.

beam bridge

The center section of the Interstate-35W (I-35W) ________ in north Minneapolis, Minnesota, suddenly gave way on August 1, 2007.

bridge

Investigators studied various questions to determine why the bridge ______ or if a combination of factors caused the bridge to fail.

collapsed

The group that contains the same factors as the experimental group, but the independent variable does not change, is called the _________.

control group

A type of scientific investigation that tests how one factor affects another is called a(n) __________.

controlled experiment

All the factors in an experiment that do not change are called _________.

controls/constants

Evaluating why the collapse occurred was difficult because emergency workers unintentionally ________ the bridge.

damaged

A(n) _________ is a force applied to a structure from the structure itself.

dead load

The factor a scientist observes or measures during an experiment is the _______.

dependent variable

Investigators could not determine if the undersized plates were used because of a mistaken calculation, a(n) __________ error, or some other error in the design process.

design/drafting

The failure of the bridge was a surprise because the design and ________ processes that bridges undergo are supposed to ensure that bridge failures do not happen.

engineering

The part of a controlled experiment used to study relationships among variables is the ______.

experimental group

Inspection of recovered __________ showed that some of the plates failed very early in the collapse.

gusset plates

The beams in the bridges deck and the triangular and vertical supports came together at structures known as _______.

gusset plates

A factor in an experiment that is manipulated or changed by the investigator is called the _______.

independent variable

Temporary loads to a structure such as traffic, wind gusts, or earthquakes are called ________.

live load

One disadvantage of beam bridges is that they tend to sag in the middle if they are too _________.

long

The area where the truss structure connects to the roadway portion of the bridge gusset plate is called a(n) __________.

node

After thorough modeling and analysis, investigators ruled out the idea that the bridge failed due to being ________.

overloaded

Investigators eventually recovered the entire structure and placed the various pieces in their relative original ________.

positions

Data that use words to describe what is observed in an experiment are called ________.

qualitative data

The use of numbers to describe what is observed is called __________ data.

quantitative

In order for investigators to determine why the bridge failed, they needed to use many parts of ________.

scientific inquiry

The I-35W bridge was a(n) ________ designed in the early 1960s.

truss bridge

A(n) truss bridge is supported only at its two ends, but it is strengthened by an assembly of interconnected triangles, or ________.

trusses

Any factor in an experiment that can have one or more value is called a(n) _________.

variable

Investigators found more clues in a(n) _________ from a motion-activated security camera.

video