**Potential Energy**** NGSS MS PS3-2**

**Potential Energy**

**NGSS MS PS3-2**

In the Potential Energy mini unit, students make connections between science and their lives as they identify all types of energy they have used today! They break down the energy changes that occur in a bouncing ball, collect data about ball drop height and bounce height and then make an excellent graph with TAILS (Title, Axes, Intervals, Labels, Scale).

Extension activities challenge students to see the fun of elastic potential energy by designing, building and testing a catapult to fling a marshmallow!

**Anchor Phenomenon Ideas**: Kids, even middle schoolers, love to play. Gather a variety of balls and toys and let your students play! Discuss how energy relates to the balls and toys and use the questions your students come up with to make connections throughout your unit.

**Make it Relevant**: Energy is all around us but it can be a difficult idea for students to fully comprehend. Focus on making connections between how kids use energy everyday and how that energy changes forms.

**Tips and Tricks:** The ball dropping lab in question four is easier to do with partners. As students increase ball drop height, they should see a corresponding increase in height of first bounce. This makes sense when looking at the formula for potential energy:

**PE =(mass in kg )(gravity 9.81m/s**^{2}**) (height in m)**

The force of gravity is constant and the mass of the ball does not change. As height increases, your total potential energy will also increase.

If students are stuck on question five, "How does gravitational potential energy affect the total energy in the bouncing ball system?" ask them if changing the potential energy of the ball also changes its kinetic energy. Did the total amount of energy of the ball increase, decrease or stay the same?

Nuts, string and tape make easy, inexpensive pendulums.

The University of Colorado PhET simulation Pendulum Lab captures the change in PE and KE as a pendulum swings. Students can collect data for the summative assessment using this simulation or just play around and gain a deeper understanding of energy within a system.

If students are building pendulums for the final lab, demonstrate how and where to place the pendulums in your room. Then, discuss how students can increase the potential energy in the pendulum system (change the starting position of the bob) and what evidence they should collect to support their claim (number of swings, total time moving). This is excellent review of experimental design and using evidence to support conclusions.

**Enrichment Ideas:** Fossil fuels are an excellent source of potential energy but they are quickly being used up. Challenge students to learn more about other sources of energy including biodiesel fuels. Ask kids if a car could really run on french fry oil!

**Extension Activity: **Building catapults to maximize elastic potential energy is a favorite middle school activity! We encourage you to build time into your schedule for all kids to try this project. Students who are ahead of pace will have more time to refine their design while students who are behind pace will still have a chance to build one machine.