Solve the Problem $\mathrm { s } = \mathrm { t } ^ { 2 } - 7 \mathrm { t } + 4$

question 208

Multiple Choice

Solve the problem.
-The position of a body moving on a coordinate line is given by $\mathrm { s } = \mathrm { t } ^ { 2 } - 7 \mathrm { t } + 4$ , with $\mathrm { s }$ in meters and $\mathrm { t }$ in seconds. When, if ever, during the interval $0 \leq t \leq 7$ does the body change direction?

• A) t = 7 sec
• B) t = 14 sec
• C) t = 3.5 sec
• D) no change in direction

---

Definitions:

Flynn Effect

The observed rise over time in standardized intelligence tests scores, attributed to various factors including improved nutrition and education.

Ethnic Groups

Categories of people who identify with each other based on common ancestral, social, cultural, or national experiences.

Decades

Periods of ten years, often used as a measure of time to note changes, trends, or developments.

Mean IQ Scores

The average score derived from standardized intelligence testing, used as an indicator of relative intelligence across a population.