1 / 30

EVD

EVD. Physical Forces. EVD Physical Forces. Directly Influence Control Offer Boundaries If Maintained – safe operation If Exceeded – loss of control. Ref. Unit IV LP 1 (Lesson 8). EVD Physical Forces. Forces Acting on an Emergency Vehicle Velocity Friction Inertia Momentum Reaction

august
Download Presentation

EVD

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EVD Physical Forces

  2. EVDPhysical Forces • Directly Influence Control • Offer Boundaries • If Maintained – safe operation • If Exceeded – loss of control EVD Ref. Unit IV LP 1 (Lesson 8)

  3. EVDPhysical Forces • Forces Acting on an Emergency Vehicle • Velocity • Friction • Inertia • Momentum • Reaction • Centrifugal Force • Centripetal Force EVD Ref. Unit IV LP 1 (Lesson 8)

  4. EVDPhysical Forces • Inclement Weather • Excessive Acceleration • Inappropriate Braking • Sudden Direction change EVD Ref. Unit IV LP 1 (Lesson 8)

  5. EVDPhysical Forces • Velocity • (Speed) • “Rate of change of position in relationship to time • V = 35 feet every second (35 ft/sec) • V = 55 miles every hour (55 MPH) EVD Ref. Unit IV LP 1 (Lesson 8)

  6. EVDPhysical Forces • Velocity Control • Acceleration • + Acceleration • Deceleration • - Acceleration • (Coasting) • Braking • Deceleration using Friction EVD Ref. Unit IV LP 1 (Lesson 8)

  7. EVDPhysical Forces • Friction • “Resistance to motion between to moving objects that are in contact with each other.” • Generates HEAT • Steering Friction • Tire/Road Friction • Brake Friction EVD Ref. Unit IV LP 1 (Lesson 8)

  8. EVDPhysical Forces • Friction • Tire/Road • Greatest – Stationary • Ok – Motion on Dry, Smooth Road • Least – Locked/Spinning • Locked – Wheel NOT turning • Spinning – Wheel FREE turning EVD Ref. Unit IV LP 1 (Lesson 8)

  9. EVDPhysical Forces • Friction • Brakes • Brakes on Drums / Pads on Discs • Friction Generates Heat • Heat Causes Brake Fade • Will Break-down Bonding Material • Heat/Expand Brake Fluid EVD Ref. Unit IV LP 1 (Lesson 8)

  10. EVDPhysical Forces • Brakes • Shoes / Drums • 90%-10% / Contact-Cooling • Excessive Heat = Less Contact • Pad / Disc • 85%-15% / Cooling-Contact • Excessive Heat = More Contact EVD Ref. Unit IV LP 1 (Lesson 8)

  11. EVDPhysical Forces • Brakes • Locking Wheels • Threshold Braking EVD Ref. Unit IV LP 1 (Lesson 8)

  12. EVDPhysical Forces • Inertia • “The force it takes a moving object to stay in motion in the same direction.” EVD Ref. Unit IV LP 1 (Lesson 8)

  13. EVDPhysical Forces • Newton’s First Law: The Law of Inertia “An object continues in its state of rest, or uniform motion in a straight line, unless it is acted upon by a net external force.” EVD Ref. Unit IV LP 1 (Lesson 8)

  14. EVDPhysical Forces • Newton’s First Law: The Law of Inertia • Objects resist change • More Mass = More Inertia EVD Ref. Unit IV LP 1 (Lesson 8)

  15. EVDPhysical Forces • Momentum • Mass x Velocity EVD Ref. Unit IV LP 1 (Lesson 8)

  16. EVDPhysical Forces • Newton’s Second Law: The Law of Momentum “When an unbalanced force acts on an object, the object will be accelerated. The acceleration will vary directly with the applied force and will be in the same direction as the applied force. It will vary inversely with the mass of the object.” EVD Ref. Unit IV LP 1 (Lesson 8)

  17. EVDPhysical Forces • Newton’s Second Law: The Law of Momentum • More momentum = more energy to change • 1 lb @ 1 ft/sec = 1 unit of momentum • Momentum & Intertia:WORK AGAINST THE DRIVER EVD Ref. Unit IV LP 1 (Lesson 8)

  18. EVDPhysical Forces The Law of Conservation of Momentum “When two objects interact, exactly equal and opposite forces result; positive and negative forces balance out.” “For a collision occurring between two objects, the total momentum before the collision is equal to the total momentum after the collision.” EVD Ref. Unit IV LP 1 (Lesson 8)

  19. EVDPhysical Forces The Law of Conservation of Momentum EVD Ref. Unit IV LP 1 (Lesson 8)

  20. EVDPhysical Forces • Reaction • “For every action there is an equal and opposite ‘reaction.’” EVD Ref. Unit IV LP 1 (Lesson 8)

  21. EVDPhysical Forces • Newton’s Third Law: The Law of Reaction “For every action there is an equal and opposite reaction.” EVD Ref. Unit IV LP 1 (Lesson 8)

  22. EVDPhysical Forces • Newton’s Third Law: The Law of Reaction • Tires push “backward” on the road • Road pushes “forward” on vehicle EVD Ref. Unit IV LP 1 (Lesson 8)

  23. EVDPhysical Forces • Centrifugal Force • An inertial force which moves a body away from the center of rotation. EVD Ref. Unit IV LP 1 (Lesson 8)

  24. EVDPhysical Forces • Centripetal Force • Forces directing the body towards the center of rotation. • Gravity • Friction EVD Ref. Unit IV LP 1 (Lesson 8)

  25. EVDPhysical Forces • Centripetal Force vs. Centrifugal Force • Forces acting in direct contrast to Centrifugal force. EVD Ref. Unit IV LP 1 (Lesson 8)

  26. EVDPhysical Forces • Directional Control • Steering • Turning • “Tracking” curves EVD Ref. Unit IV LP 1 (Lesson 8)

  27. EVDPhysical Forces • Potential Energy • Capability – i.e. Coiled Spring • Relative to position • “Stored” energy EVD Ref. Unit IV LP 1 (Lesson 8)

  28. EVDPhysical Forces • Kinetic Energy • Relative to motion • = ½mv2 • m = mass • v = velocity EVD Ref. Unit IV LP 1 (Lesson 8)

  29. EVDPhysical Forces • Control • ONLY • VELOCITY • & DIRECTION EVD Ref. Unit IV LP 1 (Lesson 8)

  30. EVDPhysical Forces • Control • Velocity • Acceleration • Change in Velocity • + Acceleration = increase • - Acceleration = decrease • (Deceleration) • Double Mass = Double Acceleration • Generally thought of in the + EVD Ref. Unit IV LP 1 (Lesson 8)

More Related