Weight in an Elevator (Phenomenon)

Contributor
3-2-1 Contact: Children’s Television Workshop HomeschoolDad5280
Type Category
Instructional Materials
Types
Animation/Movie , Phenomenon
Note
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.

Reviews

Description

A boy rides up an elevator in a tall building (the World Trade Center), with a scale under his arm.  Upon reaching the top, he stands on the scale and watches what happens to his weight as he rides down.  NOTE: For this phenomenon, start the video at 1:21 and play until 2:36.

Intended Audience

Learner
Educational Level
  • Grade 8
  • Grade 7
  • Grade 6
  • Middle School
Language
English
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

MS-PS2-5 Conduct an investigation and evaluate the experimental design to provide evidence that fields exist between objects exerting forces on each other even though the objects are not in contact.

Clarification Statement: Examples of this phenomenon could include the interactions of magnets, electrically-charged strips of tape, and electrically-charged pith balls. Examples of investigations could include first-hand experiences or simulations.

Assessment Boundary: Assessment is limited to electric and magnetic fields, and limited to qualitative evidence for the existence of fields.

This resource was not designed to build towards this performance expectation, but can be used to build towards it using the suggestions provided below.

Comments about Including the Performance Expectation
This video clip can serve as an introduction to an investigation of gravity, a force that acts through fields. Students should be encouraged to watch the video and be prepared to share what they observe, and what they wonder about. These student questions and observations can form the start of a Driving Questions board for a storyline or unit about forces working in fields.

Science and Engineering Practices

This resource was not designed to build towards this science and engineering practice, but can be used to build towards it using the suggestions provided below.

Comments about Including the Science and Engineering Practice
Students may have many questions about this phenomenon, offering several branches for further investigation. Possible questions may include: If he’s getting closer to the earth, why is he getting lighter? Is he really getting lighter, or is something else happening? What exactly is weight, anyway? How does a scale work? Is gravity even involved here, and if so, how? What would happen to his weight if he rode upward while standing on the scale? For students new to the Practice of questioning, it may be interesting to also watch the clip from 12:45 to 13:00 which features adults from the elevator asking questions about the phenomenon and engaging in light banter about it. The adults are modeling the Practice, as well as showing that science is a thing that people can talk and wonder about, and enjoy, even if science is not their career.

Disciplinary Core Ideas

This resource was not designed to build towards this disciplinary core idea, but can be used to build towards it using the suggestions provided below.

Comments about Including the Disciplinary Core Idea
An explanation of the phenomenon will need to include the role of gravity in weight and in the scale’s functioning. Student questions about how a scale works or what it means to weigh a certain amount can lead to investigations into this core idea.

This resource was not designed to build towards this disciplinary core idea, but can be used to build towards it using the suggestions provided below.

Comments about Including the Disciplinary Core Idea
An explanation of the phenomenon will need to include the concept that gravity is one of the forces (but not the only force) acting on the scale. A possible misconception is that there is no field involved because the scale is touching the floor of the elevator, and the boy is touching the scale. A teacher can help guide students’ investigations by asking them where gravity “comes from”, and asking students for personal experiences that show that it is acting even when things are not directly touching each other. If students are practicing information gathering, they might later on use the video from 12:01 to 12:40 as one of their sources, in which the boy explains in simple terms why his weight changes.

Crosscutting Concepts

This resource was not designed to build towards this crosscutting concept, but can be used to build towards it using the suggestions provided below.

Comments about Including the Crosscutting Concept
A focus on this CCC may arise from student questions about why the boy’s weight changed. The students can be encouraged to think of the boy/scale/elevator as a system, and factors such as forces and the motion of the elevator as inputs, and the reading on the scale as an output. What in the system is changing, that causes the scale reading to change as a result? The small change of his motion is resulting in a large change in his weight. Students may also wonder: is the weight loss related to the kid’s original weight, or to the speed of the elevator, or something else? Would everyone “lose” 15 pounds, or would everyone “lose” ¼ of their weight…? A related investigation that students can do in the classroom with masses and spring scales is available at https://www.thirteen.org/edonline/ntti/resources/lessons/gravity/b.html Scroll down to “Lab Experiment 1: It’s a Matter of Weight”. Though the given instructions are teacher-driven, students could instead be given the materials and asked to design their own investigations.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This resource is a phenomenon.

  • Instructional Supports: - none -

  • Monitoring Student Progress: - none -

  • Quality of Technological Interactivity: This resource does not involve technological interactivity.