Phy 101: Fundamentals of Physics I - PCC

Phy 101: Fundamentals of Physics I - PCC

Phy 101: Fundamentals of Physics I Chapter 10: Projectiles & Satellite Motion Lecture Notes Johannes Kepler (15711630) German mathematician Mathematical contributions: led to the development of calculus Derived the first proof of how logarithms work Discovered 2 regular polyhedrons Astronomy contributions:

Calculated the most exact astronomical tables of his time (using stolen data) Demonstrated that the planets move in elliptical orbits around the sun Coined the term satellite to describe the moons of Jupiter observed by Galileo Projectile Motion 2-dimension motion that occurs at the surface of the earth Key ideas Vertical motion is treated like free fall Horizontal motion is constant Horizontal & vertical components of motion occur

independent of each other Consider a ball that rolls off a flat table-top: Upwardly Launched Projectiles Satellite Motion Toss a ball horizontally: it falls to the ground

Toss the ball harder: It falls further away from you Toss the ball even harder: It falls still further away from you Now, imagine tossing a ball so hard that:

As it falls it follows the curvature of the earth This is referred to as satellite motion As the objects falls: it never reaches the earth It remains in constant free fall v Elliptical Orbits When an object in projectile motion is moving so fast that its fall does not follow the curvature of the earth it will

Overshoot a circular orbit Follow an elliptical orbit The speed of the object will vary while in elliptical orbit: closer to the earth it will move faster Farther from the earth it will move slower Keplers Laws of Planetary Motion Kepler derived a set of generalized statements describing the motion of the planets, based on the observations of Tycho

Brahe These statements are know known as Keplers Laws: 1) Each planet moves in an elliptical orbit with the sun at one focus of the ellipse 2) The line from the sun to any planet sweeps equal areas of space in equal time intervals 3) The squares of times of revolutions (periods) of the planets are proportional to the cubes of their average distances from the sun: T2 ~ R3 {for all planets} Energy Conservation & Satellite Motion When objects maintain satellite motion their energy is conserved: PE + KE = constant value This is true whether the orbit is circular or elliptical

Circular orbit: v and KE will remain constant Elliptical orbit: v and KE will vary When the satellite is closest to the planet (PE is lowest) its speed (& KE) is its fastest value for the orbit When the satellite is farthest from the planet (PE is highest) its speed (& KE) is at its lowest value for the orbit In both cases, KE + PE remains the same value Escape Speed The speed a hurled object must exceed to escape the

gravitational influence of a planet To determine escape speed: vescape = (2.gplanet.d)1/2 Or (refer to Ch 9 for details on gravitational force) vescape = (2.G.M/d)1/2 Question: How fast must an object be moving to escape the earths gravity? Bottomline: Object must have more KE than PE to escape the gravitational influence (field) of a planet!

Recently Viewed Presentations

  • Approach to the dizzy patient - McGill University

    Approach to the dizzy patient - McGill University

    Approach to the dizzy patient By: Laurence Poliquin-Lasnier R2 Neurology Epley maneuver Key feature is the roll-across in the plane of the posterior canal so that the clot rotates around the posterior canal and out into the utricle Fistula testing...
  • CAPACITY BUILDING FOR CLIMATE CHANGE MITIGATION IN THE

    CAPACITY BUILDING FOR CLIMATE CHANGE MITIGATION IN THE

    The UNCLOS includes extensive references to the protection of the environment. ... no objection member state after a certain period has elapsed, ascension to treaty assumed. Domestication of International Conventions Laws and Regulations.
  • What do these pictures have in common?

    What do these pictures have in common?

    Instead of claiming that God is outside of time, we can conceive of God as having always existed and existing infinitely into the future. He has no beginning and no end but he exists within time alongside his creation.
  • SCALE, SCALE MODELS, AND SKELETONS Keller  APHG 2011

    SCALE, SCALE MODELS, AND SKELETONS Keller APHG 2011

    APHG . 2011. Professional Development Night, AP Readings ... Fractional Scale = representative fraction. Scale gives us a concept for creating a model of the earth in either three dimensions (a globe) or two dimensions (a map). ... Not just...
  • Computer-Aided Design

    Computer-Aided Design

    NAME:SARTAZ TOPIC: Computer-Aided Design BRANCH: MECHANICAL SUBJECT: CAD/CAM YEAR : 4-1
  • The Hugh Lee Newell Story - Everyone Goes Home

    The Hugh Lee Newell Story - Everyone Goes Home

    It started after Amarillo, Texas, firefighter Brian Hunton was killed by being ejected, which we discussed in a previous slide. Will you sign it? * Although it sounds silly to drill on wearing seat belts, it isn't. Putting on all...
  • General Purpose packages What is a General Purpose

    General Purpose packages What is a General Purpose

    General Purpose packages What is a General Purpose Package (GPP)? A piece of software that allows the user to provide their own input to achieve many different types of output.
  • What is Bandwidth - Valencia College

    What is Bandwidth - Valencia College

    (differentiate between measuring storage and measuring bandwidth) Would it take less time to send the contents of a floppy disk full of data (1.44 MB) over an ISDN line or to send the contents for a 10-GB hard drive full...