# ALEX Classroom Resource

## Gravity and Falling Objects

Classroom Resource Information

Title:

Gravity and Falling Objects

URL:

https://aptv.pbslearningmedia.org/resource/phy03.sci.phys.mfe.lp_gravity/gravity-and-falling-objects/

Content Source:

PBS
Type: Lesson/Unit Plan

Overview:

We often take the force of gravity for granted, even though Earth's gravity is what keeps each of us from floating off into space! In this lesson, students begin to more fully understand and appreciate the force of gravity. They predict what will happen when a whole apple and half an apple are dropped at the same time from the same height then test their predictions. Next, they observe cannonballs of different masses being dropped out of a tower, and leaking cups being dropped into a bucket. These activities demonstrate that all objects fall at the same rate, regardless of their mass--a concept known as the law of falling bodies. Students then watch a video segment showing a NASA astronaut dropping a feather and a hammer on the Moon. They repeat the activity in the classroom then consider why these objects fall at the same rate on the Moon but not on Earth. Finally, they use what they have just learned to predict what will happen when two balls of the same mass but different volumes--and then two balls of different masses but the same volume--are dropped at the same time from the same height.

Content Standard(s):
 Science SC2015 (2015) Grade: 5 6 ) Construct an explanation from evidence to illustrate that the gravitational force exerted by Earth on objects is directed downward towards the center of Earth. Unpacked Content Scientific And Engineering Practices:Constructing Explanations and Designing SolutionsCrosscutting Concepts: Cause and EffectDisciplinary Core Idea: Motion and Stability: Forces and InteractionsEvidence Of Student Attainment:Students: Support an explanation with evidence that the gravitational force exerted by Earth on objects is directed down.Teacher Vocabulary:construct explanation gravitational force evidence illustrate sphericalKnowledge:Students know: The Earth's shape is spherical. That objects dropped appear to fall straight down. That people live all around the spherical Earth, and they all observe that objects appear to fall straight down.Skills:Students are able to: Construct an explanation of observed relationships. Use evidence to illustrate the relationship between gravity and objects on Earth.Understanding:Students understand that: If Earth is spherical, and all observers see objects near them falling directly "down" to the Earth's surface, then all observers would agree that objects fall toward the Earth's center. Since an object that is initially stationary when held moves downward when it is released, there must be a force (gravity) acting on the object that pulls the object toward the center of the Earth.AMSTI Resources:AMSTI Module: Earth: Gravity and Space Alabama Alternate Achievement Standards AAS Standard: SCI.AAS.5.6- Identify examples of objects being affected by Earth's downward gravitational force.
Tags: Earth, falling, gravitational force, gravity