Newton’s First Law (1642- 1727) • “The Law of Inertia” • A body remains at rest or moves in a straight line at a constant speed unless acted upon by a net force. – Objects do not accelerate unless a net http://teachertech.rice.edu/Participants/louviere/Newton/ne wton.html ; http://www.library.usyd.edu.au/libraries/rare/modernity/new ton3.html
Newton’s First Law (1642-1727). “The Law of Inertia” A body remains at rest or moves in a straight line at a constant speed unless acted upon by a net force. Objects do not accelerate unless a net force is applied. - PowerPoint PPT Presentation
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Newton’s First Law (1642-1727)
• “The Law of Inertia” • A body remains at
rest or moves in a straight line at a constant speed unless acted upon by a net force.– Objects do not
Newton’s 3rd Law of MotionAction Force: A guy is pushing a ball leftwards
Reaction Force: the ball is pushing the guy rightwards
Tug-a-war • If Fido and Rover play tug-a war, how do the “pulls” of the dogs compare?
• If each dog pulls with 50 N of force, what is the tension force in the middle of the rope (between the dogs)?
• While driving, Mrs. Ingle observed a bug striking the windshield of her car. The bug hits the windshield and the windshield hits the bug. Which of the two forces is greater: the force on the bug or the force on the windshield? EXPLAIN!
Putting Newton's Laws of Motion Together• An unbalanced force must be exerted for
a rocket to lift off from a launch pad or for a craft in space to change speed or direction (First Law).
• The amount of thrust (force) produced by a rocket engine will be determined by the rate at which the mass of the rocket fuel burns and the speed of the gas escaping the rocket (Second Law).
• The reaction, or motion, of the rocket is equal to and in the opposite direction of the action, or thrust, from the engine (Third Law).