Standard 3/Middle School/Benchmark 2
Benchmark Question: How do forces affect the motion of
Focus Question: How can the motion of objects be
affected by balanced and unbalanced forces?
Each student will thread a
string at least five meters long through a drinking straw and tie the
string between two chairs that are set at least four meters apart so that
the string is taut. The teacher will inflate the balloon (“hotdog” type
balloons work best) and twist and hold the end to keep it inflated (do not
tie). The teacher will attach the balloon with tape to the drinking straw
with the twisted end closest to one chair. When releasing the balloon, the
teacher will ask students, “What started the balloon moving?” and “What
happened as the balloon was released?” Using the terms “balanced” and
“unbalanced forces,” students will explain the motion of the balloon.
Discussion should include the terms found in the Key Concepts.
Students should be able to
set up their own investigations and write formal lab reports for the second
activity. The teacher will give each small group a wooden block with a
sturdy eye hook on two opposite ends, two spring scales, and a flat surface
to work on. Students will design and carry out an investigation to
determine the effects of balanced and unbalanced forces on the motion of
the block. Students will record data. Each student will write a lab report describing
the investigation. Each student will discuss their results using the terms
in the Key Concepts.
Students should have access
to reference materials that could assist them in their investigation design
(e.g., encyclopedias, science textbooks, etc.).