**Goal:** Interpreting graphs

**Source:** CT151.2-5

An

object’s motion is described by the graph above. The average

acceleration during the first 10 s is most nearly…

- 0 m/s
^{2} - 20 m/s
^{2} - 30 m/s
^{2} - 40 m/s
^{2} - 50 m/s
^{2} - Other

**Goal:** Interpreting graphs

**Source:** CT151.2-5

An

object’s motion is described by the graph above. The average

acceleration during the first 10 s is most nearly…

- 0 m/s
^{2} - 20 m/s
^{2} - 30 m/s
^{2} - 40 m/s
^{2} - 50 m/s
^{2} - Other

## Commentary:

## Answer

(3) Students may have difficulty understanding what they are

asked. Recasting the problem in terms of areas helps. The only

contenders should be #2 or #3. Counting blocks should make it clear that

the result is much closer to #3.