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Motion and Velocity. Ft. Per Second. Meters/Sec. Displacement in Time and Space. MPH. Machines, Mechanisms and Motion are Intimately Related. Work = Force x Distance.
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Motion and Velocity Ft. Per Second Meters/Sec. Displacement in Time and Space MPH
Machines, Mechanisms and Motion are Intimately Related Work = Force x Distance Machines Produce Work by Transforming Energy or Changing the Direction or Distance Through Which a Force Acts
Motion or Movement is a Change In Position Called Displacement Position A 10 ft. Position B
Speed is the Rate of Displacement 0 10 10 ft. Seconds Position A Position B
Velocity is the Rate of Displacement in a Specified Direction 0 10 10 ft. Seconds Position A Position B North West East South
Speed Equations An object’s speed is a function of Displacement(change in position) and Time(change in time between positions)
Speed Equations A simple and useful version of the Speed Equation Looks Like This
If You Want to Know the Distance Traveled You Can Rewrite the Equation Like This
200 160 Time 120 Distance in Feet 80 40 0 1 2 3 4 5 6 7 8 9 Time in Seconds Position-Time Graphs Distance (ft) Vs. Time (sec.) Distance 1 20 2 40 3 60 4 80 5 100 6 120 7 140 8 160 9 180 Describes the Rate of Change in Position of an Object Over Time
200 160 120 Distance in Feet 80 40 0 1 2 3 4 5 6 7 8 9 Time in Seconds Position-Time Graph Distance (ft) Vs. Time (sec.) Rise Run The Slope is Equivalent to the Average Speed
200 160 120 Distance in Feet 80 40 0 1 2 3 4 5 6 7 8 9 Time in Seconds Position-Time Graph Distance (ft) Vs. Time (sec.) Rise 80 ft. Run 4 sec. Speed = 20ft/sec. How Fast is this Object Moving?
200 160 120 Distance in Feet 80 40 0 1 2 3 4 5 6 7 8 9 Time in Seconds Position-Time Graph Distance (ft) Vs. Time (sec.) The constant slope indicates that the speed of the object remains constant The Slope of this Line Remains Constant Throughout the Graph
200 160 120 Distance in Feet 80 40 0 1 2 3 4 5 6 7 8 9 Time in Seconds Position-Time Graph Distance (ft) Vs. Time (sec.) The Speed of This Object Changes Over Time C B The Object is Accelerating A Speed @A = 5 ft/sec Speed @B = 24 ft/sec Speed @C = 50 ft/sec
Average Speed Time Graphs 50 40 30 Speed in ft/second 20 10 0 1 2 3 4 5 6 7 8 9 Time in Seconds Describes the speed of an object at specific times and the total displacement but NOT the Direction Study this graph and answer the questions that follow
Average Speed Time Graphs 50 40 30 Speed in ft/second 20 10 0 1 2 3 4 5 6 7 8 9 Time in Seconds How fast was this thing moving, 5 Seconds after it began to move? Hint: It began moving after 1 second
Average Speed Time Graphs 50 40 30 Speed in ft/second 20 10 0 1 2 3 4 5 6 7 8 9 Time in Seconds Answer: 40 ft/second
Average Speed Time Graphs 50 40 30 Speed in ft/second 20 10 0 1 2 3 4 5 6 7 8 9 Time in Seconds What was the total Displacement of this thing? How far did the thing go during the whole trip?
Average Speed Time Graphs 50 40 30 Speed in ft/second 20 10 0 1 2 3 4 5 6 7 8 9 Time in Seconds Answer: This Thing Traveled a total of 175 Feet Distance = Speed x Time. Therefore the total distance is the sum of the areas of each of the 5 rectangles! Try it….It works.
Another Difference Between Speed and Velocity Scalar Quantities (One Number) Vector Quantities (More Than One Number) One Gallon Distance Speed (MPH) Voltage Machine Screw Specification(tpi,length,diameter,head style) Pant Sizes(Waist and Length) Velocity (Speed and Direction) Velocity is a Vector Quantity Speed is a Scalar Quantity
Vectors Graphically Describe DIRECTION and MAGNITUDE + + = One Foot/sec One Foot/sec One Foot/sec 3 Feet/sec And You can Add and subtract Them!
Scaling Vectors 6 MPH 6 Inches 6 Centimeters A Vector Describing a Velocity of 6 MPH is Drawn With a Length of 6 Units The Length of a Vector is Proportional to It’s Magnitude
B2 A2 C2 Vectors Can Describe Displacement 10 miles East Point C Point B Total Displacement 12.2 miles North East of the Starting Position 7 miles North The Black Dashed Line is called the Resultant Point A The magnitude of the Resultant Vector is found using the Pythagorean Theorem. A2 + B2 = C2
Now…….Get Moving! The End