Energy Chain Reaction Demo Guide

Objective: To observe and identify the transformation of potential energy into kinetic energy and back again through a chain reaction.

Materials:

• Dominoes (at least 10-15)
• Toy car
• Small ramp (can be made from cardboard or a book propped up)
• Small ball (like a ping-pong ball or marble)
• Books or blocks to create elevation for the ramp

Setup:

1. Domino Line: Set up a line of dominoes, close enough so that when one falls, it knocks over the next.
2. Car Placement: At the end of the domino line, place the toy car so that the last domino will fall and hit the car.
3. Ramp Setup: Position the ramp so the car can roll down it. Use books or blocks to elevate one end of the ramp, creating an incline.
4. Ball Placement: Place the small ball at the bottom of the ramp, in the path of the toy car.

Instructions (Teacher Script - for demo):

1. Introduction: "Today, we're going to observe a 'chain reaction' that shows how energy changes forms. I want you to pay close attention to where objects are still, where they start moving, and what happens when they hit something else." (2 minutes)
2. Initial State: "Look at the dominoes, the car, the ramp, and the ball. Right now, are they moving? What kind of energy do they mostly have because of their position?" (Guide students to understand potential energy). (3 minutes)
3. Initiate Reaction: "I am going to gently push the first domino. Watch carefully what happens to the energy!" Push the first domino. (1 minute)
4. Observation: Allow the entire chain reaction to play out: dominoes fall, hit the car, car rolls down the ramp, hits the ball, and the ball moves. (2 minutes)
5. Discussion - Analyze the Chain Reaction: (7 minutes)
   • "What happened to the first domino when I pushed it? What kind of energy did it gain?" (Kinetic Energy)
   • "When the dominoes were standing, they had potential energy. What happened to their potential energy as they fell?" (It transformed into kinetic energy.)
   • "What happened when the last domino hit the toy car?" (The car gained kinetic energy.)
   • "The car was at the top of the ramp before it moved. What kind of energy did it have there? What happened as it rolled down?" (Potential energy transformed into kinetic energy.)
   • "What happened when the car hit the ball?" (The ball gained kinetic energy and moved.)
   • "Can you identify any moments where kinetic energy might have turned back into potential energy, even for a brief moment?" (e.g., if the ball rolled up a slight incline and then stopped, or the car paused briefly before rolling).

Wrap-up: "This chain reaction is a perfect example of energy transformation. Energy didn't just disappear or appear out of nowhere; it simply changed from one form to another, moving from one object to the next." (optional, can be done during the 'Explain & Define' part of the lesson using the slides).

Energy Transformation Worksheet: Shape-Shifting Energy!

Name: _____________________________
Date: ______________________________

Instructions: Read each scenario carefully. Identify the main energy transformations occurring. In the space provided, explain how potential energy (PE) changes into kinetic energy (KE), or vice-versa.

Part 1: Identifying PE and KE

For each image or scenario, label whether the object primarily has Potential Energy (PE) or Kinetic Energy (KE). Some might have both, but focus on the primary form of energy described.

1. A car parked at the top of a hill.
   Energy Type: __________________

2. A child swinging at the very bottom of their swing arc.
   Energy Type: __________________

3. A diver standing on a high diving board.
   Energy Type: __________________

4. A skateboarder speeding down a ramp.
   Energy Type: __________________

5. A stretched spring in a toy gun.
   Energy Type: __________________

6. A soccer ball flying through the air after being kicked.
   Energy Type: __________________

Part 2: Describing Energy Transformations

Describe the energy transformations in the following scenarios. Explain how PE changes to KE, or KE changes to PE, and when each is highest.

1. A rollercoaster car climbing the first big hill and then rushing down.
   
   
   
   
   
   
   
   
   
   
   
   

2. Dropping a bouncy ball from your hand.
   
   
   
   
   
   
   
   
   
   
   
   

3. A pendulum swinging back and forth. (Think about its highest points and its lowest point).
   
   
   
   
   
   
   
   
   
   
   
   

4. A person pulling back the string of a bow and then releasing an arrow.
   
   
   
   
   
   
   
   
   
   
   
   

Part 3: Real-World Energy Transformation

Think about something you do in your daily life. Describe an example of energy transformation that happens during that activity.

Example Activity: _____________________________

Energy Transformation:

Energy Transformation Worksheet: Shape-Shifting Energy! - Answer Key

Part 1: Identifying PE and KE

1. A car parked at the top of a hill.
   Energy Type: Potential Energy (PE)
   Thought Process: The car has height, giving it stored energy due to gravity. It is not moving.

2. A child swinging at the very bottom of their swing arc.
   Energy Type: Kinetic Energy (KE)
   Thought Process: At the bottom of the swing, the child is moving at their fastest speed and has the least height.

3. A diver standing on a high diving board.
   Energy Type: Potential Energy (PE)
   Thought Process: The diver is at a significant height, storing gravitational potential energy. They are not yet moving.

4. A skateboarder speeding down a ramp.
   Energy Type: Kinetic Energy (KE)
   Thought Process: The skateboarder is in motion and has picked up speed down the ramp.

5. A stretched spring in a toy gun.
   Energy Type: Potential Energy (PE)
   Thought Process: The spring is compressed/stretched, storing elastic potential energy. It is not moving.

6. A soccer ball flying through the air after being kicked.
   Energy Type: Kinetic Energy (KE) (and some PE if it's still rising or high in the air, but primarily KE due to motion)
   Thought Process: The ball is in motion due to the force of the kick, giving it energy of motion.

Part 2: Describing Energy Transformations

1. A rollercoaster car climbing the first big hill and then rushing down.

   • Climbing the hill: The rollercoaster uses external energy (e.g., a motor) to increase its height, converting kinetic energy (from the motor) into gravitational potential energy (PE). At the very top of the hill, its PE is at its highest, and its KE is momentarily low (or zero if it pauses).
   • Rushing down: As the car descends, its height decreases, and its potential energy (PE) is transformed into kinetic energy (KE). At the bottom of the hill, its KE is at its highest, and its PE is at its lowest.

2. Dropping a bouncy ball from your hand.

   • Holding the ball: The ball has maximum potential energy (PE) due to its height.
   • Falling: As the ball falls, its height decreases, and its PE is transformed into KE. Just before it hits the ground, its KE is at its maximum.
   • Bouncing up: When the ball hits the ground, some KE is lost (as sound, heat, and deformation), but much of it is used to compress the ball (storing elastic PE), which then expands, converting that elastic PE back into KE to propel it upwards. As it rises, its KE is transformed back into PE until it reaches its peak height (where KE is momentarily zero).

3. A pendulum swinging back and forth. (Think about its highest points and its lowest point).

   • At the highest points (ends of the swing): The pendulum bob is momentarily still, reaching its maximum height. Here, its energy is almost entirely potential energy (PE).
   • Swinging downwards: As the pendulum falls from its highest point, its height decreases, and its PE is transformed into KE. Its speed increases.
   • At the lowest point (bottom of the swing): The pendulum bob is moving at its fastest speed and has its minimum height. Here, its energy is almost entirely kinetic energy (KE).
   • Swinging upwards: As the pendulum rises towards the other side, its speed decreases, and its KE is transformed back into PE until it reaches the highest point on the other side.

4. A person pulling back the string of a bow and then releasing an arrow.

   • Pulling back the string: The person applies force to the bowstring, storing elastic potential energy (PE) in the bent bow limbs and stretched string.
   • Releasing the string: When the string is released, the stored elastic PE is rapidly transformed into kinetic energy (KE), which is then transferred to the arrow, causing it to fly forward with high KE.

Part 3: Real-World Energy Transformation

Example Activity: Riding a Bicycle Uphill and Downhill

Energy Transformation:

• Riding uphill: Chemical energy from the rider's body (stored in muscles) is converted into kinetic energy to move the bike and then into gravitational potential energy (PE) as the bike gains height.
• At the top of the hill: The bike (and rider) have maximum PE.
• Riding downhill: The PE is transformed into KE as the bike speeds up, often without pedaling. Some energy is lost to friction and air resistance (transformed into heat and sound energy).

Energy Transformation Cool Down

Name: _____________________________
Date: ______________________________

Quick Check for Understanding

1. Name one thing you learned about energy today.
   
   
   
   

2. Provide one real-world example of energy transforming from one form to another. Clearly state the initial and final energy forms.
   
   
   
   
   
   
   

3. In your own words, briefly explain the Law of Conservation of Energy.