7th grade Lesson on Forces and Constant of Proportionality
SPI 0707.11.4 Identify and explain how Newton’s laws of motion relate to the movement of
objects.
7.RP.A.2 Recognize and represent proportional relationships between quantities.
Part A. View two separate video clips, draw and explain what you observed
Good Jump
Bad Jump
Part B. Analyze the evidence from both videos: What is the most significant difference
between these two jumps? Explain your answer using your knowledge of the Newton’s
Laws.
Part C. Using the evidence observed, conduct an experiment using: a one-gallon Ziploc
bag, a doll (golf- ball representing a constant mass sitting on the bag) and different masses
(balls such as tennis, ping pong, racquetball, baseball, etc.) representing others jumping
into the giant floating device (one gallon Ziploc bag).
1. Before starting, make an inference about what will happen as you use different balls
representing different masses falling onto the bag. Will these different balls have the
same effect on the doll (golf ball) sitting on the bag?
2. For each different mass, students will calculate the force being generated to move
the doll using the formula F= M X A.
3. Using a measuring tape, students will measure the height achieved by the doll/golf
ball as a result of the ball dropped onto the bag.
4. Complete the table for each drop:
Mass (kilograms)
Force (Newton)
Height (meter)
Part D. Partner Work: What is direct variation? How are two measurements (force/mass
and acceleration) directly proportional?
Part E. Assessment: Using the graph provided, graph the data. Write an equation for the
data collected.
7th grade MSP Sep 2105- CMCSS Training