Newtons laws

Newtons laws

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  Newton’s Laws ofMotion Red - Write it Teks: 8.6a- Demonstrate and calculate how unbalanced forces change the speed or direction of an object in motion 8.6b- differentiate between speed, velocity and acceleration Blue - Highlight it
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  1. Motion: A change in Position A. Distance vs. Displacement 1. Distance: the entire path of travel OR how far you went. 2. Displacement: the straight line measurement (distance) between starting & ending points (including direction).
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  2. Speedvs. Velocity Speed: distance traveled divided by the time needed to travel. Velocity: displacement (although distance is usually used) divided by time including direction of travel. Formula: s = d/t Mathematically, Speed and Velocity are the SAME; Velocity adds a direction
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  3.Graphing Speed: distanceover time Constant Speed (top) As the time changes, the distance changes. The steeper the slope, the faster the speed (more distance in less time). The shallower the slope, the slower the speed (more time to cover less distance). Object at rest (bottom) As the time changes, the distance remains unchanged.
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  4. AccelerationAcceleration: change in velocity divided by the time needed for the change. Since acceleration is a change in velocity , If you change direction, even without changing speed, you are accelerating! Slowing down is also considered acceleration! It is called negative acceleration . Formula: (final velocity – initial velocity) time
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  5. GraphingAcceleration: velocity over time Section A: acceleration Section B: no acceleration; constant velocity Section C: negative acceleration
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  6. Newton’sLaws of Motion To understand Newton’s Laws: Force: a push or pull with a size and direction. Balanced forces: 2 forces that are equal but in opposite directions, canceling each other out. Unbalanced forces: when one force is greater than another, causing a change in motion. Measured in newtons, N .
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  7. 1st Law of Motion Objects resist changes in motion! If an object is at rest, it will stay at rest* If an object is in motion, it will stay in motion* *Unless acted on by a force! Also known as: The Law of Inertia More mass = more inertia
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  8. 2nd Law of Motion An object acted on by an unbalanced force will accelerate in the direction of the force. Mass (m) & Acceleration (a) affect force (F). Formula: F = ma When falling, acceleration is due to gravity and is a constant: 9.8 m/s 2
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  9. 3rd Law of Motion For every action, there is an equal but opposite reaction. When a force is exerted on an object, the object exerts the same amount of force.
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  10. Forceof Gravity: Mass V. Weight B. Mass The amount of matter an object has, regardless of any outside force being applied. On the Moon, your mass would remain the same, but your weight would change. C. Weight The force of gravity multiplied by mass. An object’s weight can change, depending on the pull of gravity. On Earth, it’s calculated as mass X 9.8 m/s 2 Measured in Newtons. Gravity: the force of attraction that exists between any two objects that have mass.
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  11. Friction:A. a force that resists motion & is always present between 2 moving surfaces Rolling friction: friction between a surface and a wheel as the wheel rolls. Sliding friction: friction that occurs when 2 surfaces slide past each other, slowing down the moving object. Static friction: Friction that hinders a stationary object from moving on a surface when a force is applied.
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  12. AirResistance: A special form of Friction Why does the feather fall more slowly than the elephant? Acceleration due to gravity is constant at 9.8 m/s 2 ; therefore, the elephant should hit with a stronger force, but not faster. The action of air molecules ‘catch’ on the surface area of an object and slow it down. According to Galileo, without air resistance, both objects would hit the ground at the same time!
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  B. Galileoproved right! While on the Moon, the Apollo astronauts proved Galileo correct. Although they dropped a hammer, not an elephant, the two objects landed at the same time. C. Acceleration due to gravity is a constant – 9.8 m/s 2 Acceleration is not affected by the mass of the object! (but slowing down is effected by air resistance)
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  Special note: Answerto number 6 on page 22:postiive