Learning Activity

Rolling Balls

Subject Area

Science

Grade(s)

8

Overview

This learning activity should be used during a lesson to make predictions, record observations, and create a hypothesis to help fully understand the relationship between potential and kinetic energy. Students will observe and record the results of three different balls rolling down an inclined plane towards a cardboard box. Students will hypothesize the reason the balls made the cardboard box move. 

This activity results from the ALEX Resource Development Summit.

Science (2015) Grade(s): 8

SC15.8.13

Create and analyze graphical displays of data to illustrate the relationships of kinetic energy to the mass and speed of an object (e.g., riding a bicycle at different speeds, hitting a table tennis ball versus a golf ball, rolling similar toy cars with different masses down an incline).

Unpacked Content

UP:SC15.8.13

Vocabulary

  • Graphical display
  • Data
  • Kinetic energy
  • Motion
  • Mass
  • Speed linear
  • Nonlinear
  • Proportional

Knowledge

Students know:
  • Kinetic energy is energy that an object possesses due to its motion or movement.
  • Kinetic energy increases if either the mass or the speed of the object increases or both.
  • Kinetic energy decreases if either the mass or the speed of the object decreases or both. The relationship between kinetic energy and mass is a linear proportional relationship (KE ∝ m).
  • In the linear proportional relationship, the kinetic energy doubles as the mass of the object doubles.
  • In the linear proportional relationship, the kinetic energy halves as the mass of the object halves.
  • The relationship between kinetic energy and speed is a nonlinear (square) proportional relationship (KE ∝ v2).
  • In the nonlinear proportional relationship, the kinetic energy quadruples as the speed of the object doubles.
  • In the nonlinear proportional relationship, the kinetic energy decreases by a factor of four as the speed of the object is cut in half.

Skills

Students are able to:
  • Develop a graphical display of data that illustrates the relationships between kinetic energy and the mass and speed of an object.
  • Use observations from the display of data to provide causal accounts for events and make predictions for events by constructing explanations.

Understanding

Students understand that:
  • The relationship between kinetic energy, mass, and speed is proportional.

Scientific and Engineering Practices

Analyzing and Interpreting Data

Crosscutting Concepts

Scale, Proportion, and Quantity
Science (2015) Grade(s): 8

SC15.8.16

Apply the law of conservation of energy to develop arguments supporting the claim that when the kinetic energy of an object changes, energy is transferred to or from the object (e.g., bowling ball hitting pins, brakes being applied to a car).

Unpacked Content

UP:SC15.8.16

Vocabulary

  • Law of Conservation of Energy
  • Argument
  • Claim
  • Kinetic Energy
  • Energy Transfer
  • System

Knowledge

Students know:
  • Kinetic energy is energy that an object possesses due to its motion or movement.
  • Changes in kinetic energy may include changes in motion, temperature, or other observable features of an object.
  • When the kinetic energy of an object changes, energy is transferred to or from that object.
  • When the kinetic energy of an object increases or decreases, the energy of other objects or the surroundings within the system increases or decreases, indicating that energy was transferred to or form the object.
  • The Law of Conservation of Energy states that in a closed system, the total energy of the system is conserved and energy is neither created nor destroyed.

Skills

Students are able to:
  • Make a claim about a given explanation or model for a phenomenon, including the idea that when the kinetic energy of an object changes, energy is transferred to or from that object .
  • Identify and describe the given evidence that supports the claim.
  • Evaluate the evidence and identify its strengths and weaknesses.
  • Use reasoning to connect the necessary and sufficient evidence and construct the argument.
  • Present oral or written arguments to support or refute the given explanation or model for the phenomenon.

Understanding

Students understand that:
  • The law of conservation of energy states that in a closed system, the total amount of energy remains constant and energy is neither created nor destroyed.
  • Energy can be converted from one form to another, but the total energy within the system remains fixed.
  • Energy can be transferred between objects in the system.

Scientific and Engineering Practices

Engaging in Argument from Evidence

Crosscutting Concepts

Energy and Matter

Phase

During/Explore/Explain
Learning Objectives

Learning Objectives

  • I will discover that the larger the mass of an object, and the higher the incline, the more energy is stored.
  • I will compute average distances. 
  • I will make predictions, record observations, and create a hypothesis. 

Activity Details

Students will observe and record the results of three different balls rolling down an inclined plane and hypothesize about the reason the distance the box changed.

  1. Pass out Student Sheet.
  2. Place masking tape to form a starting line and a line to help realign the box after it has been hit.
  3. Have students fill in the prediction section of the Student Sheet.
  4. One member of the group will roll one ball at a time down the inclined plane starting with the smallest ball and ending with the largest ball.
  5. One member will measure the distance that ball moved the box and record on the Student Sheet. (Remind students to measure in centimeters.)
  6. One member will reset the box after it has been moved by the ball and retrieve the ball that was rolled.
  7. Repeat four times for each ball, then calculate the average distance.
  8. Students should complete the Student Sheet.

The class should come back to the whole group and the teacher should ask the following questions:

  1. Which ball had the most kinetic energy? Why?
  2. What are some examples of storing and using energy in our world? (See-saws, Dams, etc.)
  3. What factors affect the amount of work an object can do? (Height and Mass).
  4. What would happen if the smallest ball was released at twice the height of the largest ball?
  5. Demonstrate releasing the smallest ball at twice the height, while another student releases the largest ball is at the original level.
  6. Discuss the results of the teacher/student demonstration.
  7. Discuss how the law of conservation of energy was observed in this Learning Asset.
Assessment Strategies

Assessment Strategies

The teacher will assess student understanding by reviewing each student’s student sheet.

The teacher will also observe student conversations to check for understanding.

Variation Tips

The teacher may want to discuss the following questions prior to implementing the Learning Activity:

  1. If I place the balls on top of an inclined plane, would the balls have any type of energy? Why? Yes, the balls would have a type of energy. At rest, the ball will have potential energy (PE). When the balls are released down the inclined ramp, the potential energy changes to kinetic energy (KE).
  2. Which ball do you think will have the most potential energy?

The teacher may want to demonstrate how to roll the ball down the inclined plane and how to measure the distance the box was moved.

The teacher may gather materials and have students set up inclined planes and cardboard boxes.

Background and Preparation

Background / Preparation

The teacher should gather the following materials to complete this learning asset:

  • Print Student Sheet
  • 3 balls of different sizes and weights
  • Inclined Plane
  • Meter stick
  • Cardboard Box
  • Masking Tape
  • Calculators

The teacher should set up inclined planes with platforms at the top so that balls can be rolled down the inclined plane for this Learning Asset.  Also, the teacher should place cardboard boxes at the bottom of an inclined plane.  

Digital Tools / Resources

Rolling Balls
https://docs.google.com/document/d/1YDveIVayg8ulvGFLztw-13vk5uaUARnha9sJYU_FRkU…

Approved Date

Owner (Author)

yvetteakridge
ALSDE LOGO

This site may contain links to other websites or content belonging to or originating from third parties or links to websites and features in banners or other advertising. Such external links are not investigated, monitored, or checked for accuracy, adequacy, validity, reliability, availability, or completeness by us. WE DO NOT WARRANT, ENDORSE, GUARANTEE, OR ASSUME RESPONSIBILITY FOR THE ACCURACY OR RELIABILITY OF ANY INFORMATION OFFERED BY THIRD-PARTY WEBSITES LINKED THROUGH THIS SITE.
Alabama Learning Exchange © 2002-2023 by Alabama State Department of Education is licensed under Attribution-NonCommercial-ShareAlike 4.0 International

Design by Adaptive Theme