CH.1 FORCE AND VELOCITY
CH.1 FORCE AND VELOCITY MAIN IDEAS
F&M: 1.5.1 WARM-UP Students consider how the presence or absence of friction affects the motion of objects. (10 min) Take a few minutes and individually respond to the Warm-Up. Friction:a force between an object and the surface it is moving over scussion about the homework article "Friction
F&M: 1.5.1 WARM-UP
F&M: 1.5.1 WARM-UP What did you learn from the article about the direction of the force exerted by friction? How does friction affect moving objects? If you see an object moving across a surface and slowing down, what can you assume? It acts in the opposite direction to the way an object is moving. There must be friction. It slows them down.
Outer space is mostly empty there is almost no matter in the huge spaces between stars and planets. Since friction is a force between an object and the surface it is moving over, can friction exist if an object is moving through empty space? Assuming the pod that moved away from the space station doesn t run into another object, what do you expect will happen to the It will pod? keep moving at the same velocity forever. F&M: 1.5.1 WARM-UP No. Friction is not a factor for objects moving in space and prompt students to think about how that affects ACM pods. If there is no friction to slow these objects, what will happen to their velocity? It won t change unless a force is exerted on the o
F&M: 1.5.2 FORCE STRENGTH AND VELOCITY CHANGE Students work with a partner to complete missions in the Sim where they test their understanding of the relationship between force strength and velocity change. (15 min) SIM - Build on their ideas about how stronger or weaker forces can cause different changes in velocity. - In order to be successful with the missions, you need to keep the direction of force in mind.
F&M: 1.5.2 FORCE STRENGTH AND VELOCITY CHANGE
Demonstrate how to use Prepare Forces panel. Explain that students should be setting up a single force for each mission. Show students that to set up a force, they should press PREPARE FORCE at the top of the screen, then press the arrow in the Force panel that points in the direction they want to exert the force. They can press the arrow multiple times to exert a stronger force. Show students that when they are satisfied with the force they have set up, they will click EXERT FORCE, which will exert the force and allow them to observe the results. F&M: 1.5.2 FORCE STRENGTH AND VELOCITY CHANGE
F&M: 1.5.2 FORCE STRENGTH AND VELOCITY CHANGE
F&M: 1.5.2 FORCE STRENGTH AND VELOCITY CHANGE
F&M: 1.5.2 FORCE STRENGTH AND VELOCITY CHANGE Record the change in velocity in their data tables once the mission is successful.
F&M: 1.5.2 FORCE STRENGTH AND VELOCITY CHANGE A stronger force is needed to cause a greater change in velocity and a weaker force causes a smaller change in velocity.
F&M: 1.5.2 FORCE STRENGTH AND VELOCITY CHANGE CLASS DISCUSSION - Discuss the pattern you notice with force and velocity change Key Point - A larger force causes a greater change in velocity and a smaller force causes a smaller change in velocity.
F&M: 1.5.3 MODELING FORCE AND VELOCITY Students create digital models to show that greater velocity changes are caused by stronger forces. (20 min) Modeling Tool allows you to visually communicate your understanding of force and changes in velocity. You will be developing more sophisticated models as you progress in the Force and Motion unit.
Before Force panel: Drag velocity tails to the left or right side of an object so they show the object s initial velocity. During Force panel: Drag force arrows to an object so it shows the force exerted (direction and strength). After Force panel: Drag velocity tails to the left or right side of an object so it shows the effect of the force. F&M: 1.5.3 MODELING FORCE AND VELOCITY
F&M: 1.5.3 MODELING FORCE AND VELOCITY Describe the velocity change shown in this example. [The object started moving to the right.] In which direction was the force applied that caused this change? [To the right.]
F&M: 1.5.3 MODELING FORCE AND VELOCITY HAND IN - once you press this button, you should reload your screen to see a completed screenshot of your model
F&M: 1.5.3 MODELING FORCE AND VELOCITY You used evidence to consider a cause-and-effect relationship. In the example you just looked at, you thought about the effect of the force (After Force panel) and figured out the direction of the force that caused this effect (changing the object s velocity from not moving to moving to the right). Using evidence and reasoning to explain how or why something happens is an important skill in science. infer: to reach a conclusion using evidence and reasoning
F&M: 1.5.3 MODELING FORCE AND VELOCITY Remember! Return to Amplify Science screens to see a screenshot of your wo Use evidence about changes in velocity to infer the strength and direction of force that was applied to each object Add annotations to your screenshots to explain their thinking
F&M: 1.5.3 MODELING FORCE AND VELOCITY This shows that greater velocity changes are caused by stronger forces.
F&M: 1.5.3 MODELING FORCE AND VELOCITY What causes some velocity changes to be greater than others?
F&M: 1.5.3 MODELING FORCE AND VELOCITY Object A must have had a stronger force acting on it because it had a greater change in velocity.
F&M: 1.5.3 MODELING FORCE AND VELOCITY
F&M: 1.5.3 MODELING FORCE AND VELOCITY
F&M: 1.5.3 MODELING FORCE AND VELOCITY If you know a force has been exerted on an object, you can predict how the velocity changed. You can infer both the direction and force strength, based on the resulting change in velocity.
F&M: 1.5.3 MODELING FORCE AND VELOCITY