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Objects in MOTION…….. Travel by foot Travel by wheels

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Presentation on theme: "Objects in MOTION…….. Travel by foot Travel by wheels"— Presentation transcript:

1 Objects in MOTION…….. Travel by foot Travel by wheels
Travel by animal Travel by wheels Travel by motor on land Travel in air by planes (Flight) Travel through space (Rockets)

2 Motion is defined as a change of location or position of an object with respect to time.
One speaks of motion in terms such as velocity, acceleration, displacement, and time. Velocity is defined as the rate of change of position– (5m/sec due north) Acceleration is defined as the change of velocity over time. It can imply both a change in speed or a change of direction or both. It is measured in meter/second2. A car accelerates as it changes its speed The moon accelerates as it revolves around from 10m/hr to 50m/hr The earth because its position is changing.

3 Force = mass x acceleration F = ma
A change in motion requires an applied force (push or pull). Force: any influence that causes a free body to accelerate. Force = mass x acceleration F = ma Force and acceleration are directly proportional. The greater the force, the greater the acceleration. Mass and acceleration are inversely related. The greater the mass of an object the less the acceleration if the same force is applied. 100 N = 50kg x 2m/s2 Smaller the mass the greater the acceleration 100 N = 25kg x 4m/s2

4 The larger the Force the greater the Acceleration
Acceleration: 4m/sec2 Acceleration: 2 m/sec2 F= (50)(4) 200N = 200kg x m/s2 F= (50)(2) 100N = 100kg x m/s2

5 Man’s continued advancement in improving his means to move greater distances in shorter time involved understanding the forces involved, Understanding: Gravity (force that pulls matter to earth) Friction (force that opposes motion) sliding, rolling, static Air resistance (type of friction that opposes the movement of objects in air) Drag: Force due to fluid resistance-acts opposite to the direction of motion Thrust: Mechanical force generated by the engines in a car/airplane/- acts in the direction of motion Improvements in materials and better use of machines led to improved means of transportation ….of push carts, ……….bicycles…., cars…….planes…….rockets

6 What forces are involved to propel the bike?

7 Propulsion: motor (force to drive the system)
(Creates thrust) Guidance: handlebars used to steer Control: hand brakes Suspension: wheel- serves to give a smooth ride for passenger. Identify one important property of the material used to make the wheel…..(durable, flexible, rough, thick,) Explain why the property you identified in part (b) is important for the scooter…. Must provide some friction and protect from bumps, rocks…..etc

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9 Invention of motors - converts chemical energy
into thermal and kinetic energy which creates thrust. Early cars…..steam, electric, gas

10 Which of the following best describes an advantage of using a mass production manufacturing system instead of a custom manufacturing system? Henry Ford’s ingenuity in mass production allowed for cars to be made at a much lower cost thus they became available to more people? As the world was turning from horse power to the 20 horse power engine of Henry Ford’s cars in 1908, he turned out 10,607 Model T 's. This began a 19 year production run, making 15,000,000 little cars that changed the world. October The Ford Motor Company made the first Tin Lizzie for $850. Innovative assembly line production cut the price of the "Common Man's Car" to $350 by 1926.

11 The diagram below shows a Formula 1 racing car
The diagram below shows a Formula 1 racing car. Many forces act together on the racing car so it can move safely at high speeds on a racetrack. Thrust: Thrust is the force created by the motor which propels the car forward. Drag: Drag is the force due to air resistance causing the car to slow down. Gravity: Gravity is the force keeping the car on the ground.

12 Thoughts for Solar car How will you create thrust for your solar car?
What will produce drag for your car? How will you minimize drag? What material will you consider for your chassis? Wheels?

13 Drag is the force due to air resistance
causing the car to slow down.

14 From Ground to Air……..What will it take?
Your assignment will be to create a timeline of Flight History……but first…….. The Forces of Flight

15 What force is recognized and controlled
in man’s search to understand FLIGHT?

16 Bernoulli’s Principle:
principle that states that as the speed of a fluid increases, its pressure decreases Airplane wings are designed to use Bernoulli’s principle air traveling over the wings moves faster than air underneath this reduces the pressure on top of the wing, allowing it to be pushed upward All that is necessary to create lift is to turn a flow of air.

17 Pressure is greater in the stationary fluid (air) than in the moving fluid (water stream). The atmosphere pushes the ball into the region of reduced pressure.

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20 There are many factors that affect the turning of the flow, which creates lift. We can group these factors into(a) those associated with the object, (b) those associated with the motion of the object through the air, and (c) those associated with the air itself: Object: At the top of the figure, aircraft wing geometry has a large effect on the amount of lift generated. The airfoil shape and wing size will both affect the amount of lift. Motion: To generate lift, we have to move the object through the air. The lift then depends on the velocity of the air and how the object is inclined to the flow. Air: Lift depends on the mass of the flow. The lift also depends in a complex way on two other properties of the air: its viscosity and its compressibility.

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23 Thrust is the force which moves an aircraft through the air
Thrust is the force which moves an aircraft through the air. Thrust is used to overcome the drag of an airplane, and to overcome the weight of a rocket. Thrust is generated by the engines of the aircraft through some kind of propulsion system. Thrust is a mechanical force, so the propulsion system must be in physical contact with a working fluid to produce thrust. Thrust is generated most often through the reaction of accelerating a mass of gas. Since thrust is a force, it is a vector quantity having both a magnitude and a direction. The engine does work on the gas and accelerates the gas to the rear of the engine; the thrust is generated in the opposite direction from the accelerated gas. The magnitude of the thrust depends on the amount of gas that is accelerated and on the difference in velocity of the gas through the engine. The physics involved in the generation of thrust is introduced in middle school and studied in some detail in high school and college. To accelerate the gas, we have to expend energy. The energy is generated as heat by the combustion of some fuel. The thrust equation describes how the acceleration of the gas produces a force. The type of propulsion system used on an aircraft may vary from airplane to airplane and each device produces thrust in a slightly different way. We will discuss four principal propulsion systems at this web site; the propeller, the turbine,or jet, engine, the ramjet, and the rocket.

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26 Thrust is generated by the engines of the aircraft /car/scooter through some kind of propulsion system.

27 Propulsion A balloon-propelled car was raced. As the air escaped backwards from the balloon (Action Force) the car ran forwards as a result of Reaction Force of the escaping air. Thrust is used to overcome The weight of a rocket Chemical rocket engines use the combustion of propellants to produce exhaust gases as the working fluid. The high pressures and temperatures of combustion are used to accelerate the exhaust gases through a rocket nozzle to produce thrust.

28 Thrust is the force which moves an aircraft through the air.
Thrust is used to overcome the drag of an airplane, and to overcome the weight of a rocket.

29 thrust is used in opposition to weight.
Thrust is the force which moves the rocket through the air, and through space. Thrust is generated by the propulsion system of the rocket through the application of Newton's third law of motion; For every action there is an equal and opposite re-action. In the propulsion system, an engine does work on a gas or liquid, called a working fluid, and accelerates the working fluid through the propulsion system. The re-action to the acceleration of the working fluid produces the thrust force on the engine. The working fluid is expelled from the engine in one direction and the thrust force is applied to the engine in the opposite direction

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