Puff Mobile (Arevalo)

Author(s)

Akiko Arevalo - Marquez Charter School, Pacific Palisades, CA

NGSS Engineering Standards

ETS1.A: Defining and Delimiting Engineering Problems

• A situation that people want to change or create can be approached as a problem to be solved through engineering. (K-2-ETS1-1)

• Asking questions, making observations, and gathering information are helpful in thinking about problems. (K-2-ETS1-1)

• Before beginning to design a solution, it is important to clearly understand the problem. (K-2-ETS1-1)

ETS1.B: Developing Possible Solutions

• Designs can be conveyed through sketches, drawings, or physical models. These representations are useful in communicating ideas for a problem's solutions to other people. (K-2-ETS1-2)

ETS1.C: Optimizing the Design Solution

• Because there is always more than one possible solution to a problem, it is useful to compare and test designs. (K-2-ETS1-3)

PS2.A: Forces and Motion: Each force acts on one particular object and has both strength and a direction. An object at rest typically has multiple forces acting on it, but they add to give zero net force on the object. Forces that do not sum to zero can cause changes in the object's speed or direction of motion. (Boundary: Qualitative and conceptual, but not quantitative addition of forces are used at this level.) (3-PS2-1)

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 addresses as a force that pulls objects down.]

Materials needed

• For Puff Mobiles:

  • large index cards

  • mint lifesavers (individually wrapped)

  • jumbo drinking straws

  • 1" wide masking tape (30cm strips)

  • large paper clips

  • plastic sandwich bags

• For Teacher/Organization:

  • brown paper lunchbags (for "shopping" and storage)

  • bags of money ($700 of Monopoly money in different denominations)

  • Monopoly "bank" (for "cashier" at the store)

  • price tags on materials

  • product cost sheet

Procedure

• Explain to students that they are engineers employed by a Toy company. It would like to create a toy car out of miscellaneous materials that does not need any electricity (batteries) to power it.

• Present students with the CHALLENGE: Build a car that travels the farthest distance.

  • Criteria: the car must roll along the ground on wheels and axles using only your breath

  • Constraints: budget of $700, only using materials provided, no returns/exchanges of used/opened items, students must work in teams of 2-4.

• Show materials, but notify them they will need to BUY them

• Each student team is given $700 and a shopping bag

• Teams must work through the EDP (engineering design process) and present detailed diagram of car along with a completed cost sheet to teacher for approval

• Teams purchase materials and build.

• Teams race prototypes and then discuss successes/challenges

• Teams improve designs and RACE AGAIN!

Questions

• What force is used to move the mobile?

  • A pushing force.

• Why is the mobile stationary when we are not blowing at it?

  • The forces acting upon it are all equal (balanced).

• Why does the mobile move when we blow at it?

  • The blowing force is greater than the other forces acting upon it.

Photos