Summary
This lesson builds upon students' understanding of gravity and guides students to understand that gravity is attractive, correlates with mass, and inversely correlates with distance. Students conduct a lab then evaluate various statements about gravity based on their understanding of the lab. At the end of the lesson, students create a Claim, Evidence, Reasoning (CER) statement in which they summarize their understanding of gravity.
Essential Question(s)
How do physical properties influence gravitational interactions?
Snapshot
Engage
Students respond to a gravity pick-up line and compare the sun to a black hole.
Explore
Students conduct a gravity bucket lab and discuss factors that influence gravity.
Explain
Students evaluate the accuracy of several statements and examine the reasoning behind each one.
Extend
Students compare and contrast the gravity on different planets in the solar system.
Evaluate
Students write a Claim, Evidence, Reasoning (CER) statement that compares a black hole to the sun.
Materials
Lesson Slides (attached)
Claim, Evidence, Reasoning handout (attached; one per student)
Gravity Bucket Lab handout (attached; one per student)
Always, Sometimes, or Never True handout (attached; one per group of three students)
Always, Sometimes, or Never True Answer Key document (attached; one for teacher use; optional)
Gravity Comparative Analysis handout (attached; one per student)
Buckets (3.5 gallon or larger; two per lab group)
Nylon fabric
Bungee cords
Scale
Baseball
Marble
Steel ball
Cue ball
Wood ball
Engage
10 Minute(s)
Use the attached Lesson Slides to guide the lesson. Introduce the lesson using the title on slide 2. Transition through slides 3–4 to introduce the essential question and lesson objectives.
Display slide 5 and share the quote, “Even if Earth didn’t have gravity, I’d still fall for you.” Have students explain why the quote is funny on a piece of paper. Invite a few students to share out their responses.
Display slide 6 and play the GIF that compares the mass of a black hole to the mass of the sun. Distribute one copy of the Claim, Evidence, Reasoning handout to each student and have them respond to the question on the slide in the left column of the handout.
Explore
30 Minute(s)
Display slide 7. Organize students into groups of three and distribute one copy of the Gravity Bucket Lab handout to each student. Have students begin conducting the lab and remind them to record data and observations. As students follow the procedures on their handouts and conduct the lab, walk around the room to assist students and answer questions as needed.
Once the majority of students have completed the lab, regain students’ attention and show slide 8. Use the questions on the slide to guide a discussion over the concepts from the lab.
Explain
25 Minute(s)
Reorganize students into new groups of three and have students bring their Gravity Bucket Lab handout along to their new group. Arrange each group so that students are grouped with any of the members from their lab groups. Present slide 9. Pass out one copy of the Always, Sometimes, or Never True handout to each group.
Encourage students to work together with their group members to determine which statements are always true, which statements are sometimes true, and which statements are never true. Allow students time to complete the handout using their prior knowledge and information from the lab.
Have students set aside their handouts in a safe place before the next activity. Do not reveal the correct answers yet.
Extend
30 Minute(s)
Have students remain in their groups. Display slide 10 and pass out one copy of the Gravity Comparative Analysis handout to each student. Have students work in their groups to read the data table present on their handout and respond to questions about the data. Encourage students to use their knowledge from earlier activities to complete the handout.
Draw students’ attention back to their Always, Sometimes, or Never True handout. Ask them if the data from the Gravity Comparative Analysis handout changed any of their responses or provided them with any new examples or non-examples.
Transition through slides 11–26 to review each statement from the Always, Sometimes, or Never True handout. Encourage students to share out how they responded to each statement, then reveal the correct response. As you share the correct categorization for each statement, ensure that you address any examples or non-examples that didn’t properly align with a statement. Assist students in understanding how their examples do fit with another statement or concept, or why incorrect examples don’t align with certain concepts.
Evaluate
15 Minute(s)
Show slide 27 and replay the video from the Engage phase that compares a black hole to the sun.
Have students return to their Claim, Evidence, Reasoning handouts. Introduce the components of a Claim, Evidence, Reasoning (CER) response using the following information present on the slide.
Claim: Write a statement about the difference between the gravitational pull of the sun compared to that of a black hole.
Evidence: Provide 2–3 examples of observations from the lab or class activities that support your claim.
Reasoning: Use scientific terminology and explanations to explain how your evidence supports your claim.
Encourage students to formulate a response that incorporates the data from the gravity bucket lab, the Gravity Comparative Analysis handout, and the statements from the Always Sometimes, or Never True activity. Remind students that they must back up their claim with specific evidence from the lesson.
Consider collecting students’ CER statements as Exit Tickets. You may also consider using these statements as a formative assessment of the lesson.
Resources
K20 Center. (n.d.). Always, sometimes, or never true. Strategies. https://learn.k20center.ou.edu/strategy/145
K20 Center. (n.d.). Bell ringers and exit tickets. Strategies. https://learn.k20center.ou.edu/strategy/125
K20 Center. (n.d.). Claim, evidence, reasoning (CER). Strategies. https://learn.k20center.ou.edu/strategy/156
NASA. (2008, October 20). BHBuckets2 [Photograph]. NASA. https://nightsky.jpl.nasa.gov/news/398/
NASA. (2008, October 20). Gravity buckets: Explore black holes and gravity with a bucket and fabric. Night Sky Network. https://nightsky.jpl.nasa.gov/news/398/
Puiu, T. (2017, March 16). The mass of a supermassive black hole relative to the Sun explained in one crazy GIF [GIF]. ZME Science. https://www.zmescience.com/space/supermassive-black-hole-vs-sun/