Exploring Center of Gravity

A white mobile with two arms. Hanging from the left arm is a solar powered paper plane. The solar panel is on the top and 2 propellors. On the right arm is a bird shaped paper plane with 3 solar panels down wing and on the back and 2 propellors.
Learning Goals

Learning Goals:

  1. Students will observe a discrepant event and write down questions about what they observed.
  2. Students will participate in a variety of activities using a meter stick in order to experience and learn about center of gravity.
  3. Students will find the center of gravity of an irregular shaped paper object by using a plumb line.
  4. Students will apply the concept of Center of Gravity and find the center of their solar aircraft that is to be used on their solar mobile.
Materials List

Handouts

  • Student Engineering Notebooks

Classroom Supplies

  • Balancing bird (example)
  • 1 box of modeling clay (divided into walnut size balls)
  • Hand held hole punch (one per table group)

Individual Supplies

  • Meter stick
  • Small ball of clay
  • File folder
  • 50cm String
  • 10cm Dowel for string
  • 2 Washers
  • Optional: 1/2 of a 20″x30″ foam board

Important Links

Next Generation Science Standards

Next Generation Science Standards

Performance ExpectationHow is this Assessed?
MS-PS3-5 Construct, use, and present arguments to support the claim that when the kinetic energy of an object changes, energy is transferred to or from the object.Students will use various solar panels and learn about solar energy transfer in order to power the motors on their solar plane. Students record this knowledge and use it for their final engineering design project.
MS-ETS1-4 Develop a model to generate data for iterative testing and modification of a proposed object, tool or process such that an optimal design can be achievedStudents work through modifications and apply what was learned about solar circuits, the center of gravity, and irradiance as they build their final model.

Lesson 3 of 5 / Time: 1-2 periods of 55 mins

Since the concept Center of Gravity (mass) is a key factor in a mobile, students will participate in some activities to help them experience and understand this principle so it can be applied to their final Solar Mobile design. This lesson starts with a teacher demonstration of the discrepant event of a bird that can balance on its beak. Then students will explore center of mass with a meter stick and balls of clay giving them some hands-on experiences. In addition, students can work with various irregular shapes cut out of file folders and find the center of mass of an irregular shape. They can follow the same process as in Center of Irregular Things and find the initial center of mass for their aircraft.

Solar Mobile Design Challenge

Download Lesson