Gravity.

Slides:

Advertisements

Similar presentations

Ch 8.1 Motion in the Heavens and on Earth

Advertisements

Circular motion and Gravitation Chapter 6 1Physics Chapter 6.

Copyright © 2009 Pearson Education, Inc. Lecture 7 Gravitation 1.

Chapter 7 Tangential Speed

Chapter 7: Circular Motion and Gravitation

TOPIC 6: Fields and Forces. What is gravity? Is there gravity in space? Why do astronauts float? What keeps the moon from flying off in space?

Objectives Solve orbital motion problems. Relate weightlessness to objects in free fall. Describe gravitational fields. Compare views on gravitation.

Chapter 7 Circular Motion and Gravitation

Physics I Honors 1 Specific Forces Fundamental Forces Universal Gravitation.

Universal Law of Gravitation Some Basics The force of gravity is the mutual attraction of objects to one another. The acceleration due to gravity.

Newton’s Law of Universal Gravitation

Newton reasoned that there is a force of attraction between every two objects in the universe.

Chapter 8 Universal Gravitation

Newton’s Law of Universal Gravitation

Newton’s Law of Gravitation. Newton concluded that gravity was a force that acts through even great distances Newton did calculations on the a r of the.

TOPIC 6.1: Gravitational Fields and Forces These notes were typed in association with Physics for use with the IB Diploma Programme by Michael Dickinson.

The Universal Law of Gravitation

Newton’s Law of Gravitation. Newton concluded that gravity was a force that acts through even great distances Newton did calculations on the a r of the.

Gravity ISCI More Free Fall Free Fall Vertical and Horizontal Components of Free Fall.

Kepler’s first law of planetary motion says that the paths of the planets are A. Parabolas B. Hyperbolas C. Ellipses D. Circles Ans: C.

Universal Law of Gravity. Newton’s Universal Law of Gravitation Between every two objects there is an attractive force, the magnitude of which is directly.

Gravity. Gravity A force of attraction between objects that is due to their masses. A force of attraction between objects that is due to their masses.

Centripetal Force and Acceleration

Newton believed that every object ___attracts_____ every other object. The force of the attraction depends on the __mass___ and _distance__ of the two.

Fast Moving Projectiles: Satellites The Earth satellite is simply a projectile that falls around the Earth rather than into it.

Gravitation. Universal Law of Gravitation Every mass attracts every mass in universe - F g. F g directly proportional to mass. –Doubling the mass of one.

One of the most significant intellectual achievements in the history of thought.

Assume stopper is at constant 2 m/s. Is it accelerating. Does it have F net. What causes F net ? Direction of F net ? Direction of acceleration? Velocity.

Chapter 5 Circular Motion; Gravitation. 1. Use Newton's second law of motion, the universal law of gravitation, and the concept of centripetal acceleration.

Laws of Motion Forces: chapter st Law An object at rest remains at rest and an object in motion maintains its velocity unless it experiences an.

Newton’s Universal Law of Gravitation

Law of universal Gravitation Section The force of gravity: All objects accelerate towards the earth. Thus the earth exerts a force on these.

Proportionality between the velocity V and radius r

SPH3U – Unit 2 Gravitational Force Near the Earth.

Topic 6: Fields and Forces 6.1 Gravitational force and field.

Universal Gravitation. Space Station link  Nasa Nasa.

Circular Motion.

Newton’s Universal Law of Gravitation Chapter 8. Gravity What is it? The force of attraction between any two masses in the universe. It decreases with.

Kepler’s Laws  Kepler determined that the orbits of the planets were not perfect circles, but ellipses, with the Sun at one focus. Sun Planet.

Universal Law of Gravitation. So because of Newton’s 3 rd law every body in the universe exerts a force of attraction on every other body. This is Newton’s.

GRAVITATION NEWTON’S LAW OF GRAVITATION There is an attractive force between any two bodies which is directly proportional to the product of their masses.

4.3 Newton’s Law of Universal Gravitation p. 140 From Kepler to Newton Newton used Kepler’s Laws to derive a law describing the nature of the gravitational.

If it is known that A is directly proportional to B, how would A change if B is increased by a factor of 2? 1. Increase by a factor of 2 2. Increase by.

Universal Gravitation Brought to you by: Ashley, Chelsey, and Jordan.

Newton’s “4 th law”. Law of Universal Gravitation 1.Gravity is universal: ALL objects attract each other. 2.The force of gravity is directly proportional.

Sect. 6-4 Satellites and “Weightlessness”. Satellites are routinely put into orbit around the Earth. The tangential speed must be high enough so that.

Universal Gravitation Ptolemy (150AD) theorized that since all objects fall towards Earth, the Earth must be the center of the universe. This is known.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Circular Motion and Gravitation Chapter 7 Table of Contents Section.

Satellite Physics & Planetary Motion Illustration from Isaac Newton, Philosophiae Naturalis Principia Mathematica, Book III Isaac Newton was the first.

FgFg agag mg g W Do you know the difference?? Newton’s Law of Universal Gravitation Every body in the universe attracts every other body with a force.

Physics Section 7.2 Apply Newton’s Law of Universal Gravitation Gravitational force (gravity) is the mutual force of attraction between particles of matter.

Kepler’s Laws What are the shapes and important properties of the planetary orbits? How does the speed of a planet vary as it orbits the sun? How does.

( ) Planetary Motion and Gravitation

3.3 Newton’s Law of Universal Gravitation

The story of the apple When Newton observed the apple fall, he wondered if the force that caused the apple to fall to the ground was the same force that.

Universal Gravitation

3.1 Force of Gravity.

Newton’s Laws of Motion

Universal Gravitation & Satellites

What is “weightlessness?”

Isaac Newton ( ) Newton’s Laws of Motion

Newton’s Law of Gravitation

Gravity and The Law of Universal Gravitation

The story of the apple When Newton observed the apple fall, he wondered if the force that caused the apple to fall to the ground was the same force that.

Universal Law of Gravitation

Newton’s Law of Universal Gravitation

Newton’s Law of Universal Gravitation

Presentation transcript:

Gravity

Newton’s Universal Law of Gravitation Newton’s conceptual leap in understanding gravity was his realization that the same force governs the motion of a falling object on Earth & the motion of the Moon in its orbit around the Earth.

Universal Law of Gravitation Every mass attracts every other mass through gravity. The force of attraction between any 2 objects is directly proportional to the product of their masses. Doubling the mass of 1object doubles Fg between the 2 objects.

Inverse Square Doubling distance between two objects weakens force of gravity by a factor of 22 (or 4). Fg drops off by ¼.

NEWTON’S UNIVERSAL LAW OF GRAVITATION GMm r2

G is universal gravitation constant. G = 6. 67 x 10-11 N m2. kg2 G is universal gravitation constant. G = 6.67 x 10-11 N m2. kg2. m1 m2 are mass of objects in kg. r is distance between ctrs m.

Gravity and Weight Definition: The weight of an object is a measure of the Fg one object feels in the presence of another. Weight Fg = mg. Where g is known.

Mass can be measured in 2 ways Inertial mass - the mass of a body as determined by its momentum, as opposed to gravitational mass. How it accelerates m = Fnet/a Gravitational mass -the mass of a body determined by its response to the force of gravity.

1. Prove that the acceleration of gravity g = GM/r2, where M is the mass of a planet or star r is its radius.

g = GM1 is accl due to gravity Fg = m2g = GM1m2. r2. g = GM1 is accl due to gravity Mass of the object cancels out. Acceleration depends only on the mass of the planet (or star).

Questions: Raise Hands. Is heavier body attracted to the Earth with more force than a light body. Does the heavier object free fall faster? Explain.

Newton’s Universal Law of Gravitation Fg = GMm. R2. Describes Force btw point masses. What is a point mass?

Gravitational Field deals with space around the mass.

Gravitational Field Strength/Intensity - Force per unit mass experienced by a small “test mass” in space.

Gravitational Field Lines drawn in direction of acceleration of small mass.

Gravitational Field = g Gravitational Field = g. The value for acceleration, g, is also called the gravitational field. Set the weight equal the Fg. The units of the gravitational field are N/kg. Since mg = GMm. The small mass m cancels r2. Grav Field g = GM units N/kg. r2. Use to find acceleration or gravitational field.

2. What is the gravitational field strength due to Earth at a point 450 km above the surface?

g = GM r2. (6.67 x 10-11)(6 x 1024kg) (6.4 x 106m + 450 x 103m)2. 4 x 1014. (6 850 000)2. 4 x 1014. 4.7 x 1013. 8.5 N/kg

Fields are vectors. Forces resulting from more than 1 field is the sum of the field strengths.

Ex 3. Two spheres lie along a straight line Ex 3. Two spheres lie along a straight line. The sphere on the left has m = 1000-kg, and the right on the right has m = 100-kg. The distance between their centers is 5-m. Point A lies between the spheres at 2.5-m from the center of each. Calculate the field strength at point A.

9.63 x 10 – 9 N/kg left

Rd Hamper 127 – 129 do pg 129 - 131. Purple boxes #1 – 5. Show all work.

Einstein vs. Newton 9.5 min http://www.youtube.com/watch?v=4yyb_RNJWUM

Orbits Maintained By Gravity

4. Derive an equation to express the minimum velocity a satellite must have to stay in orbit.

v = (GMe)1/2. (r) 1/2. GMem = mv2. r2 r Fg keeps the satellite in orbit. Set Fc equal to gravitational force. Fg = Fc GMem = mv2. r2 r v = (GMe)1/2. (r) 1/2.

5. What is the velocity needed for a satellite to stay in orbit 200 km above the Earth’s surface?

First find the total distance between their centers.

2.0 x 105 m. 6.37 x 106 m. 6.57 x 106m total r.

v = (GMe)1/2. (r) 1/2. (6.67x10-11)(5.98x1024 kg)1/2 (6.57 x 106m )1/2. 7790 m/s.

Cavendish Torsion Balance measurement of G.

Einstein vs. Newton 9.5 min http://www.youtube.com/watch?v=4yyb_RNJWUM

http://www. phy. ntnu. edu. tw/java/projectileOrbit/projectileOrbit http://www.phy.ntnu.edu.tw/java/projectileOrbit/projectileOrbit.html Newton’s Cannon Launch Satellite Apparent weightlessness. Satellites are in freefall around the Earth! That is why astronauts appear weightless. They are constantly falling toward Earth. Their rate of fall is balanced by their tangential momentum.

The universe season 2 Gravity, Roller Coasters, Space Travel & PEg. https://www.youtube.com/watch?v=EiljzeDL0co 45 minutes