# Newton's Laws of motion

Account Executive - IT/Telecom em Next-Techs
6 de Apr de 2015
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### Newton's Laws of motion

• 1. Newton’s Three Laws of Motion Sir Isaac Newton Mr. Boggio April 2015
• 3. Newton’s Contributions to Science and Math Calculus Light is composed of a color spectrum Reflecting Telescope Laws of Motion Theory of Gravitation
• 4. Newton’s First Law (Inertia) Newton's first law of motion states that an object at rest remains at rest and an object in motion remains in motion with the same velocity unless acted upon by an unbalanced force
• 5. Balanced /Unbalanced Forces Unequal opposing forces produce an unbalanced force causing motion
• 6. If objects in motion tend to stay in motion, why don’t moving objects keep moving forever? Things don’t keep moving forever because there’s almost always an unbalanced force acting upon them. A book sliding across a table slows down and stops because of the force of friction. If you throw a ball into the air it will eventually slow down and fall because of the force of gravity.
• 8. Four types of friction: • Sliding friction: ice skating • Rolling friction: bowling • Fluid friction (air or liquid): air or water resistance • Static friction: initial friction when moving an object What is the unbalanced force that acts on anWhat is the unbalanced force that acts on an object in motion?object in motion?
• 10. Newton’s Second Law Force equals mass times acceleration. F = ma
• 11. Newton’s Second LawNewton’s Second Law Force = Mass x AccelerationForce = Mass x Acceleration Force is measured in NewtonsForce is measured in Newtons Acceleration of Gravity = 9.8 m/sAcceleration of Gravity = 9.8 m/s² (32 ft/s(32 ft/s²)) Weight (force) = mass x gravityWeight (force) = mass x gravity Moon’s gravity is 1/6 of the Earth’s If you weigh 420 Newtons on earth, what will you weigh on the Moon? Ans: 70 Newtons If your mass is 41.5Kg on Earth what is your mass on the Moon? Ans: ?
• 12. Falling Objects: Humans Terminal Velocity = 120 mph = 176 ft/sec Acceleration Gravity = 9.8 m/sec² = 32 ft/sec² F = ma = 68 kg (150 lbs.) x 9.8m/sec² = 668 Newtons 1 sec 32 ft/sec 2 sec 64 ft/sec 3 sec 96 ft/sec 4 sec 128 ft/sec 5 sec 160 ft/sec 6 sec 176 ft/sec – Terminal Velocity Terminal velocity is the highest velocity attainable by an object in free fall. It occurs once the sum of the drag force (friction) Fd and buoyancy equals the downward force of gravity FG acting on the object. Since the net force on the object is zero, the object has zero acceleration
• 13. Newton’s Third Law For every action there is an equal and opposite reaction.
• 14. Newton’s 3rd Law For every action there is an equal and opposite reaction. Book to earth Table on book
• 16. Action: tire pushes on road Reaction: road pushes on tire
• 17. reaction: rocket pushes on ga action: gases push on rocket
• 18. Consider hitting a baseball with a bat. If we call the force applied to the ball by the bat the action force, identify the reaction force. (a) the force applied to the bat by the  hands (b) the force applied to the bat by the ball (c) the force the ball carries with it in  flight (d) the centrifugal force in the swing
• 19. Review Newton’s First Law: Objects in motion tend to stay in motion and objects at rest tend to stay at rest unless acted upon by an unbalanced force. Newton’s Second Law: Force equals mass times acceleration (F = ma). 2nd law applied to Gravity: Weight = mass x 9.8 m/s² or 32 ft/s² Newton’s Third Law: For every action there is an equal and opposite reaction.