Advertisement
1 / 23

Rubber Band Powered Airplanes PowerPoint PPT Presentation


  • 478 Views
  • Uploaded on 04-08-2012
  • Presentation posted in: General

Rubber Band Powered Airplanes. By Angela Coburn University of British Columbia Department of Physics and Astronomy. Outline. History of Rubber Powered Aircraft Newton’s Second and Third Law’s Four Forces Acting on an Airplane Energy, Work and Power Transport Cost Calculations - PowerPoint PPT Presentation

Download Presentation

Rubber Band Powered Airplanes

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Rubber band powered airplanes l.jpg

Rubber Band Powered Airplanes

By Angela Coburn

University of British Columbia Department of Physics and Astronomy


Outline l.jpg

Outline

  • History of Rubber Powered Aircraft

  • Newton’s Second and Third Law’s

  • Four Forces Acting on an Airplane

  • Energy, Work and Power

  • Transport Cost

  • Calculations

  • Building Airplanes

  • Summary


History of rubber powered aircraft l.jpg

History of Rubber Powered Aircraft

  • 1903 – Wright brothers made the first human flight.

  • As children they received a rubber powered toy helicopter.

  • When they broke it they started building their own.

  • This began their life long interest in flight.


History of rubber powered aircraft4 l.jpg

History of Rubber Powered Aircraft

  • 1871- Alphonse Penaud flew a rubber-powered aircraft called the planophore for 131 feet in 11 seconds.

  • first really stable aircraft, making it one of the most important inventions leading up to the invention of the airplane.


History of rubber power aircraft l.jpg

History of Rubber Power Aircraft

  • Became an important research tool for aerodynamic engineers, as it allowed them to test numerous configurations of:

    • wings

    • rudders

    • elevators

    • fuselages for airworthiness


Newton s law s of motion l.jpg

Newton’s Law’s of Motion

  • Newton’s second law states that if the forces on an object are unbalanced then its motion will change. The bigger the force, the bigger the change in motion or acceleration.

    F=ma

    (Force= mass X acceleration)


Newton s law s of motion7 l.jpg

Newton’s Law’s of Motion

  • Newton's Third Law of Motion says that when two objects push or pull against each other,the forces that they feel are equal and opposite.


Four forces acting on an airplane l.jpg

Four Forces Acting on an Airplane


How does a propeller make the aircraft move forward l.jpg

How does a propeller make the aircraft move forward?

  • The engine turns the propeller.

  • The propeller is specially shaped to push the air backwards. This results in a reaction force on the propeller that moves the aircraft forwards. (Thrust).


Energy l.jpg

Energy

  • Energy: The ability of an object do work. Has units of Joule (J) or newton-meter (Nm).

  • Kinetic Energy: Energy of motion.

    KE=1/2mv2

  • Potential Energy: Stored energy.

    Ug=mgh


Work and energy l.jpg

Work and Energy

  • Work: The amount of energy transferred by a force acting through a distance. Unit of Joule (J).

    W=F∙d

  • What about for our model airplane?


Work done by the propeller l.jpg

Work Done by the Propeller

  • The distance around the edge of a circle (or any curvy shape) is the circumference:

    C = 2πr

  • We must also count the number of times the propeller travels around the circle.

    Distance = (2πr) x turns


Power and steady state l.jpg

Power and Steady State

  • Power: The time rate of energy transfer. Unit of Watt (W) or J/s.

    P=W/t

  • Steady State:to maintain an aircraft in flight, the power input has to be equal to the power output to its surroundings.


Calculations l.jpg

Calculations

  • Using some of the equations and concepts we have just learned, let’s calculate the potential energy stored in the rubber band.


Our model airplane l.jpg

Our Model Airplane

  • Recall that the propeller provides the thrust to move the plane horizontally.

  • In the model, potential energy is stored in the twisted rubber band powering the propeller.

  • When the rubber band untwists, kinetic energy is released and work is done in turning the propeller.

  • Thus, the potential energy stored in the rubber band will be equal to the work.


Model airplane l.jpg

Model Airplane

  • Recall that Work= Force X distance

  • How can we measure the force the rubber band exerts on the propeller?

    F=mass x acceleration (9.8m/s2)

  • What about the distance?

    d= 2πr (number of turns)

  • For our model: W= F x (2πr) (number of turns)


Model airplane18 l.jpg

Model Airplane

  • Why is the energy stored in the rubber band different when we measure it again after winding the propeller back down?

    Some of the energy was lost to heat in the rubber band!


Model airplane19 l.jpg

Model Airplane

  • Now that we have calculated the work, let’s calculate the power.

  • How can we do this?

    Power = Work/time


Transport cost l.jpg

Transport Cost

  • This is the most important measure of energy use in transportation.

  • Energy consumed per unit mass per unit distance travelled.

  • Measure of energy.

  • Units of J/kg/m or kWh/tonne/km.


Slide23 l.jpg

Let’s build some airplanes!