Module 5 Universal Gravitation, Speed of Light, and Special Relativity
(10 Days)
Module Components
OverviewNewton's three laws of motion and the universal law of gravity are landmark theories in classical physics.
The universal law of gravitation describes the weakest of the fundamental forces in nature, yet it is the force that holds the universe together. The success of this law, in describing the motion of planets and stars, provides evidence that the laws of nature on Earth are universal, describing events throughout the universe. The students will learn that near Earth's surface, Newton’s gravitational law describes the gravitational attraction (weight) of objects to the Earth, but it is also the law that describes gravity as the force keeping satellites, moons, planets, and galaxies from flying apart. The historical development of ideas about gravity will begin with the legend of Newton’s falling apple and end with Einstein’s general theory of relativity, where gravity bends light and slows the passing of time. In the extreme, Einstein’s relativity predicts or accepts the possibility of science fictionlike entities of black holes, worm holes, and time travel 
Essential QuestionsWhat IS gravity?
What CAUSES gravity? In what ways does gravity hold the universe together? How does gravity affect the motion of the stars and planets? 
Knowledge & SkillsThe students will know how to describe and calculate the magnitude if the gravitational force between two objects.
Knowledge includes, but is not limited to: Masses of the objects Distance between their centers The law of universal gravitation Force of gravitational attraction between two objects = (universal gravitation constant)((mass of 1st object)(mass of 2nd object)/(distance between centers of objects)2) Fg = G (m1m2/d2) Universal gravitation constant G = 6.67 x 1011 N ∙m2/kg2 The amount of gravitational force between two objects Students will research and describe the historical development of the concepts of gravitational, electromagnetic, weak nuclear, and strong nuclear forces. Knowledge includes but is not limited to: Gravitational forces Newton Cavendish Einstein 
Key UnderstandingsThe universal law of gravitation formulated by Newton states that every two objects in the universe with mass are attracted to each other.
The history of gravity is essential to a complete understanding of its importance. Newton reasoned its general properties, Cavendish measured it, and Einstein extended it to an integrated theory of space and time. Relativity compares measurements between two frames of reference moving relative to each other. Special relativity examines the measurements at relative speeds near the speed of light. Objects moving near the speed of light will be shorter in the direction of motion and more massive and have slower clocks than measurements made by the moving object. 
MisconceptionsStudents may think that gravitational force is the same on all falling bodies.
Students may think that gravitational force acts on one object at a time. Students may think only large objects have a gravitational force. 
Key VocabularyGravitation – the force of gravity
Relativity – the theory that space and time are relative concepts, rather than absolute concepts 
Performance IndicatorsResearch and create a written report on the history of gravitational forces, including Einstein’s contributions. Use calculations to describe how the magnitude of the gravitational force between two objects depends on their masses and the distance between their centers.
Create a cartoon strip to explain the relationship between time, length, and mass measurements in two frames of reference moving relative to each other at a constant velocity. State the assumptions of special relativity, recognize when special relativity effects become important, and describe those effects 
Summative AssessmentsThis module will have the stated performance indicators as well as the unit assessment and one exam.
