3-PS2-1 Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object.
Clarification Statement: Examples could include an unbalanced force on one side of a ball can make it start moving; and, balanced forces pushing on a box from both sides will not produce any motion at all.
Assessment Boundary: Assessment is limited to one variable at a time: number, size, or direction of forces. Assessment does not include quantitative force size, only qualitative and relative. Assessment is limited to gravity being addressed as a force that pulls objects down.
This resource is explicitly designed to build towards this performance expectation.
Comments about Including the Performance Expectation
To meet this performance expectation, students create a paper rocket and carry out investigations to improve the distance their rocket travels. To aligned this activity to the performance expectation, allow students the time to explore working with balanced and unbalanced forces. Prior to the lesson, it is suggested that the teacher drop an object to the floor and ask the students, “Why did it fall? What caused it to stop falling? If you were to make a paper airplane, what could you do to make the airplane move without tossing it with your hands? Would the plane keep going forever? What would make the plane stop?” Another suggestion is to expose students to a picture/video of a tight rope walker and discuss the importance of the center of mass and how balanced and unbalanced forces are at play.
3-5-ETS1-2 Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.
Clarification Statement: none
Assessment Boundary: none
This resource is explicitly designed to build towards this performance expectation.
Comments about Including the Performance Expectation
After students design their rockets and have their first "liftoff", they are encouraged to improve their rocket design after holding distance trials. Students are provided data sheets that outline the procedures for each rocket test. However, it is suggested that students use a notebook or journal to more formally write down what worked and what did not work as they projected their rockets. Students can draw and write their reflections how how the things they changed resulted in different outcomes. It is also suggested that the teacher clearly state the criteria and constraints of the problem before the students begin to design their rockets. The criteria being that the students will create paper rockets and design them to move the greatest distance by blowing air through a drinking straw. It is suggested that the students understand a constraint could be they can give only one breath of air through the straw to launch the rocket. Teachers can consider a different alternative to the students 'blowing' to launch their rockets to be sure it is a fair test as everyone may 'blow' differently into the straw. To create a fair test and a more consistent launch would be to create a 2 liter bottle launch mechanism by 1) emptying the bottle 2) the teacher drills or cuts a hole in the bottle lid 3) putting a tube in the lid hole that will also firmly attach to the straw, and attaching it, 4) dropping a mass on the 2 liter bottle to launch the rocket. Science Olympian has guidelines for this type of consistent launching. Although the word constraints is not specifically mentioned, the list of materials the students can use is listed in the guide.