Summary
Students explore projectile motion using Newton's first law of motion.
Essential Question(s)
How do forces change a projectile's trajectory?
Snapshot
Engage
Students watch the commercial "Second Chance" and use the I Think/We Think strategy to describe how it relates to inertia and projectile motion.
Explore
Students are given the task of dropping a ball on a target while in motion.
Explain
Students work together to explain how inertia relates to projectile motion and how gravity and inertia work together to form the projectile's trajectory. Students describe the motion of the ball and sketch a line that describes the motion of the ball.
Extend
Students read an article about bombing during World War I and World War II and relate it to projectile motion, or students watch an ICAP video on an attorney and chemical engineer to consider how their careers apply to Newton's law.
Evaluate
Students reflect on the lesson by answering three overarching questions.
Materials
Lesson Slides (attached)
I Think/We Think T-chart handout (one per student, attached)
A Drop in the Bucket handout (one per student, attached)
World War II Technology that Changed Warfare (print 1 set per student)
Poster or easel pad paper (one per group of 4–5)
Paper (one sheet per student)
Tape
Markers
Sticky notes (several per group)
Buckets (3 per group of 4–5)
3-inch balls (e.g., tennis balls) (1–2 per group of 4–5)
Engage
10 Minute(s)
Use the attached Lesson Slides to guide the lesson. Display slides 3 and 4 to introduce the essential question and learning objectives.
Transition to slide 5 and show "Second Chance," a seat belt safety commercial that shows the consequences of not wearing a seat belt.
Pass out the I Think/We Think T-Chart handout and display slide 6. Use the I Think/We Think strategy by instructing students to write down their thoughts in the “I think” column on how the video demonstrates Newton's first law and inertia. After 2–3 minutes, instruct students to pair up and share their ideas to formulate one "we think" statement about the video and Newton's law.
Call on pairs to share their "we think" statements with the class. Use slides 7 and 8 to share the definitions for Newton’s first law and inertia.
Newton's first law: An object remains in motion or remains at rest until an unbalanced force is applied to the object, causing it to change its motion or state of rest.
Inertia: an object's tendency to resist changing its motion or its state of rest.
Address misconceptions and be sure that students know the key term in Newton's first law and can define inertia. Students should also know that this first law can be called Newton's law of inertia.
Display slide 9 and show the video a second time, and instruct students to sketch the motion of the man on their handout. Students will refer to this sketch later and use it as comparison to another projectile's motion.
Explore
30 Minute(s)
Take a ball and drop it vertically from one hand to the next. Ask students to explain what is happening to the ball as you drop it. Display slide 10 and introduce the ball and target activity.
Place students into groups of four or five and pass out the A Drop in the Bucket handout.
Students will explore the concept of inertia further by observing a falling ball from a moving person. Students will run toward three buckets that are placed on the floor. The goal is to drop the object into the middle bucket while other group members watch from the side to determine how the ball falls. Before they begin, have the groups brainstorm and record their ideas about the challenges of getting the ball into the middle bucket.
Display slide 11. Students take turns so everyone has a chance. Students may even record the ball drop on a device and watch it in slow replay.
Explain
40 Minute(s)
When students have finished recording data, display slide 14 and have students answer the following analysis questions on the handout:
How is the inertia of the occupants inside the car related to the inertia of the ball in your hand?
How does your sketch of the man's motion compare to the motion of the falling ball?
Are both the man and the ball considered projectiles?
What effect does gravity, paired with inertia, have on the motion of the man and the falling ball?
Next, provide each group with poster or easel pad paper, and with markers. Display slide 15 and introduce the activity. Ask them to create sketches illustrating the car (refer to Engage sketch) and ball scenarios in relation to Newton’s first law of motion and inertia. Then, have them summarize how Newton's first law and inertia apply to both scenarios.
Display slide 16 and use the Gallery Walk strategy to have groups visit each visual presentation and summaries. Give each group enough sticky notes to leave feedback on each poster. Once students have returned to their posters, have them read through the feedback and prepare to share out their understanding or any questions they may still have.
Extend
35 Minute(s)
Display slide 17 and ask the question: Beyond the classroom, where might you encounter or see a projectile that has similar motion to the man in the car and the falling ball? Allow for open, informal discussion. Call on volunteers to answer.
The article, "World War II Technology that Changed Warfare," is an excellent extension of this lesson. Pass out a copy of World War II Technology that Changed Warfare to each student. Display slide 18 and instruct students to read the introduction and pages 11–15 (Bombsights: The Advancement of Bombsights) of the reading. Have students use the Stop and Jot strategy with each page to identify the main idea from each section.
Evaluate
10 Minute(s)
Display slide 21 and give students time to think before answering the following questions on a sheet of paper. Instruct students to use key terms from the lesson.
How are the man, the ball, and the bombs from WWI and WWII all related?
Before bombsight technology and radar, what factors would have to be considered to get the falling projectile (the bomb) to hit its exact target?
In what situations is a projectile launched but the effect of gravity on the path is not easily observed, only its own inertia?
Resources
Demonstrations in physics. (n.d.). Newton’s first law of motion. https://physics.weber.edu/amiri/physicsvideos/part1/laws_of_motion/first_law/default.asp
Foley, S. (February 2011). World War II technology that changed warfare - radar and bombsights. Academic Symposium of Undergraduate Scholarship 8. https://scholarsarchive.jwu.edu/cgi/viewcontent.cgi?article=1011&context=ac_symposium
K20 Center. (n.d.). Gallery walk / carousel. Instructional Strategies. https://learn.k20center.ou.edu/strategy/118
K20 Center (2020, December 14). K20 ICAP - Attorney & chemical engineer - Buckle Up. YouTube [Video]. https://youtu.be/3OBNpJQxQrs
K20 Center. (n.d.). I think / we think. Instructional Strategies. https://learn.k20center.ou.edu/strategy/141
K20 Center. (n.d.). K20 timer - 00:00:00 https://timer.k20center.ou.edu/
K20 Center. (n.d.). Mentimeter. Tech Tools. https://learn.k20center.ou.edu/tech-tool/645
K20 Center. (n.d.). Stop and jot. Strategies. https://learn.k20center.ou.edu/strategy/168
U.S. Department of Transportation National Highway Traffic Safety Administration. (2015, May 8). Second chance [Video]. YouTube. https://www.youtube.com/watch?v=L62ueMB0E5E
Weller, M. (2024, April 11). Newton’s cradle (99/365). Flickr. https://www.flickr.com/photos/edtechie/6683410305
