Rolling Down the Hallway

Learning Resource Type

Learning Activity

Subject Area

Science

Grade(s)

8

Overview

The students will measure the speed of a tennis ball as it rolls across a flat surface.  Students will learn that because of inertia, an object tends to maintain its motion.

This activity results from the ALEX Resource Development Summit. 

Phase

During/Explore/Explain
Science (2015) Grade(s): 8

SC15.8.8

Use Newton’s first law to demonstrate and explain that an object is either at rest or moves at a constant velocity unless acted upon by an external force (e.g., model car on a table remaining at rest until pushed).

UP:SC15.8.8

Vocabulary

  • Sir Isaac Newton
  • Newton's First Law of Motion
  • Constant velocity
  • Balanced force
  • Unbalanced force
  • External force
  • Rest
  • Motion
  • Inertia

Knowledge

Students know:
  • An object at rest remains at rest unless acted on by an external force.
  • An object in motion remains in motion unless acted upon by an external force.
  • Inertia is the tendency of an object to resist a change in motion.
  • An object subjected to balanced forces does not change its motion.
  • An object subjected to unbalanced forces changes its motion over time.
  • Constant velocity indicates that an object is moving in a straight line at a constant speed.

Skills

Students are able to:
  • Demonstrate Newton's first law.
  • Articulate a statement that relates a given phenomenon to a scientific idea, including Newton's first law and the motion of an object.

Understanding

Students understand that:
  • Newton's First Law states that an object at rest remains at rest unless acted upon by an external force.
  • Newton's First Law states that an object at in motion remains in motion at a constant velocity unless acted upon by an external force.

Scientific and Engineering Practices

Constructing Explanations and Designing Solutions

Crosscutting Concepts

Cause and Effect

Learning Objectives

I will observe the motion of an object.

I will measure the speed of an object across a flat surface.

I will demonstrate Newton's First Law of Motion.

Activity Details

The student will observe the motion of a tennis ball, measure the speed of the tennis ball, and explore Newton's First Law of Motion in the following activity:

  1. Students will need to be in groups of five to six.
  2. Distribute Rolling Down The Hallway Student Sheet.
  3. Distribute timers.
  4. Students will lay down 4 meter sticks end to end placed down the hallway, gym floor, or any other flat surface.
  5. Students will place masking tape at the 1-meter, 2-meter, 3-meter, and 4-meter marks along the meter sticks. 
  6. Students should be positioned at each meter marking (1 meter, 2 meters, 3 meters, 4 meters) waiting for the ball to cross their mark.
  7. One student will be the launcher and should try his/her best to launch the tennis ball at a constant speed each time the ball is launched.
  8. As the tennis ball crosses each student's meter mark, the student at the respective marking should stop the timer.
  9. Students should record the times of meter intervals on the Rolling Down The Hallway Student Sheet.

Assessment Strategies

The teacher could assign the students the following questions on paper or have the students discuss them with group members:

  1. Is the motion of the tennis ball nearly constant or constantly changing as the ball moves down the hallway or flat surface? Students should find that the tennis ball is nearly constant.
  2. How can you provide evidence to support your answer to Question #1? Students could answer by saying you could measure the speed to see if it is constant.
  3. Is the force of the launcher’s hand still acting on the tennis ball after the tennis ball is released?  The force of the ball is no longer acting on the ball after it is released.
  4. What term is used to describe something that keeps moving at a constant speed in a straight line and remains unchanged? Inertia

The teacher could either grade the questions on paper or observe the group discussions to check for understanding of the standards.

Variation Tips

A different type of ball may be used in the Learning Activity.

Background / Preparation

The teacher will need to gather the following materials:

  1. Divide students into groups of five to six
  2. Meter sticks - enough for each group to have 4 meter sticks each
  3. Masking Tape
  4. Timer/Stopwatch
  5. Tennis Balls (Enough tennis balls for each group to have a ball)
  6. Print Rolling Down The Hallway Student Sheet 
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