Unit: Newton’s First Law of Motion
Grade: 9-12 | Content Area: Science | Course Name: Physics |
Description of Unit: During this unit students will explore Newton’s First Law of Motion. In doing this, they will understand the equilibrium of forces and constant motion. | Approximate Time Needed: 5-8 days |
Benchmarks: 2.1 I can use vectors and free-body diagrams to describe force, position, velocity and acceleration of objects in two-dimensional space. (9P.2.2.1.1)
2.2 I can recognize that inertia is the property of an object that causes it to resist changes in motion. (9.2.2.2.1)
2.3 I can apply Newton’s three laws of motion to calculate and analyze the effect of forces and momentum on motion. (9P.2.2.1.2)
2.4 I can describe the motion of objects in proper terms, graphs and equations.
Essential Questions: How does an object behave when forces are balanced?
How can the motion of an object be described?
Lesson | Duration | Supporting Target | Resources | Assessment |
1 | 1-2 days | I can use free body diagrams to describe forces on an object. I can relate an object's motion to the slope of its position versus time. I can describe the velocity of an object from the free body diagram. I can recognize that inertia is the property of an object that causes it to resist changes in motion. | Newton’s First Law Presentation | Pre |
2 | 1-2 days | I can recognize the relationship between slope and the type of motion. I can translate the motion into a free body diagram. | Constant Velocity Practice Worksheet Constant Velocity Graphing Lab | Formative |
3 | 1 day | I can explain behavior using a free body diagram. | Formative | |
4 | 1-2 days | I can use free body diagrams to describe the motion of an object. I can recognize that inertia is the property of an object that causes it to resist changes in motion. I can apply Newton’s three laws of motion to calculate and analyze the effect of forces on motion. I can describe the motion of objects in proper terms, graphs and equations. | Summative | |
5 | 1 day | I can use free body diagrams to describe the motion of an object. I can recognize that inertia is the property of an object that causes it to resist changes in motion. I can apply Newton’s three laws of motion to calculate and analyze the effect of forces on motion. I can describe the motion of objects in proper terms, graphs and equations. | Fictional Physics - Newton’s First Law | Summative |
Activity | Notes to Instructors |
Purpose: To be able to describe the motion of an object with only balanced forces on it. Materials: Air puck (purchase or build), meter sticks, stopwatch (or phone app) Students will observe the motion of an air puck across the ground and also make a graph of its motion. It is helpful to have a stopwatch or stopwatch app that has multiple splits to make data acquisition easier. However if you do this as a class, then it is easy to have multiple students get the time. Time: 20 minutes. | |
Slide 2: Other forces could include: air resistance, tension forces, spring forces, nuclear forces Slide 6: Example of an unchanged motion: Any movement at the same speed and direction (may need to go over scalar vs vector if it has not been addressed at this time) Example of a changed motion: Any time speed or direction does change. Slide 7: bowling ball, rock, bus | |
Slide 2: An object at rest remains at rest, and an object in motion remains in motion unless another forces acts on it. An object at rest or in motion has greater inertia (resistance to move) the more massive it is because a greater force must act on it. Slide 3: Other scalar quantities: volume, density, mass (recall that these were discussed in Unit 1 Presentation - Making and Using Measurements) Other vector quantities: acceleration, momentum, impulse, energy, work; these may be more difficult for students to list as they most likely will not know the meaning behind them this early in the course Slide 4: Scalar, vector, vector, scalar, scalar, vector Students may question -18 N as a vector quantity. Use it so they become familiar with Newtons as a unit of force and that a specific navigational direction is not what is needed for a vector (+ or - sign indicated direction in some cases). Slide 5: km/h, m/h, mi/h, cm/s, etc. Slide 6: 10.4 m/s Slide 8: km/h north, m/h left, cm/s south Slide 9: 20 m/s due west The car is about 2 times faster than Usain Bolt. Usain Bolt ran about 22.5 mi/h. | |
1. 4.87 m/s west 2. 7.1 m/s north 3. 0.50 cm/s east 4. 85 m 5. 4.3 h 6. one small arrow going up and one small arrow pointed down 7. one large arrow going up and one large arrow pointed down 8. one small arrow up, one small arrow down, one small arrow left and one small arrow right 9. one large arrow up, one large arrow down, one large arrow left and one large arrow right | |
Purpose: This lab will be a basic introduction to video analysis. Students will need to be able to download a video and use Quicktime to change frames. Distances can be measured within each frame and graphs will be made on the spreadsheet. Connections to the free body diagrams will be made with the motion in the questions following each video. Technology Requirement: Computer with Internet access and Quicktime Teacher’s Guide and Sample Results Ipad Alternatives: You will have to download the videos and place them in a Dropbox for the students to open. Required apps for this are Video Physics and Graphical Analysis both from Vernier. These apps have a cost, but will be used extensively. Ipad Tutorial for Video Physics and Graphical Analysis Time: 45 minutes | |
Purpose: Give students practice making free body diagrams and applying them to real world situations. Also to get students thinking about friction and what factors affect it. Materials: Shoe Spring Scale 3 Masses Two surfaces Teacher’s Guide and Answer Key Time: 45 minutes | |
Purpose: Assess student understanding of free body diagrams and Newton’s First Law of Motion Materials: Various, access to devices capable of recording and sharing video. Students are asked to come up with motions that would fit 3 graphs and then describe the motion both with words and free body diagrams. Encourage the students to be creative. The amount of time this activity takes depends on student creativity and to what extent you give them class time to get it done and how much in class time you want to spend sharing student work. It is recommended that you have students share in small groups. Sharing in the entire class will get old since all of the projects will look similar when it comes to the free body diagrams. A rubric is included as the last page of the student worksheet. Time: 45-90 minutes | |
Fictional Physics - Newton’s First Law | Purpose: Assess student understanding of free body diagrams and Newton’s First Law of Motion Students use free body diagrams to explain some cartoon weirdness. Use the first link to the presentation to introduce the students to the activity. The second link is a document for student use. Students should be given some flexibility to make up forces in order to balance the forces in each scenario. For example, when explaining how a cartoon character hovers before falling, students could make up an “ignorance force” that exactly counters the force of gravity but disappears when when he realizes falling is possible. That same “ignorance force” could balance the applied force to a character that runs from the cliff in order to get him through the tunnel, whereas the force is absent for whoever painted the tunnel. Grading Rubric is attached to the student worksheet. There are videos from Roadrunner cartoons on youtube that I you can share with the class. They couldn’t be put up here because of copyright. Time: 45 minutes |
