Simple Machines Inclined Plane Wedge and Screw Simple

Simple Machines Inclined Plane, Wedge, and Screw

Simple Machines The Six Simple Machines Mechanisms that manipulate force and distance. Lever Wheel and Axle Pulley

Inclined Plane Wedge Screw

Inclined Plane A flat surface set at an angle or incline with no moving parts Able to lift objects by pushing or pulling the load

Inclined Plane AMA 15 . 20 lb ft s b l. 50 4 ft What is the AMA of the inclined plane above? AMA = 2. 5: 1 What is the efficiency of the inclined plane above? Efficiency = = 0. 67 or 67%

Wedge • Functions as a moving inclined plane • Tapers to a thin edge • Used for splitting, raising heavy items, or tightening by expansion (being driven into something)

Wedge IMA DE = Distance traveled by the effort = L L 10. 0 in. H 3. 0 in. DR = Distance traveled by the resistance = H What is the IMA of the wedge on the right? IMA = 10. 0 in. / 3. 0 in. = 3. 33 = 3. 3: 1

250. lb Wedge AMA L 10. 0 in. H 3. 0 in. What is the AMA of the wedge on the right? 700 b 0. l . lb 70 AMA = 2. 80: 1 What is the efficiency of the wedge on the right? Efficiency = = 0. 84 or 84%

Screw Two Components: • An inclined plane wrapped around a cylinder, forming the screw’s “pitch” • A wheel and axle used to create rotary motion Properties: • • Change rotary motion into linear motion Used as a threaded fastener Large amount of friction loss (is this good or bad? ) Large MA

Screw Identification Effort Arm Distance If using a wrench, effort arm distance would be the length of the wrench Pitch Distance between threads, also the linear distance traveled in one rotation of the screw. Example: a screw has 13 threads per inch, 13 TPI for short. The pitch (distance between threads) is 1/13 of an inch. Q: How far will a screw with 13 threads per inch advance if turned one full rotation? A: 1/13 of a inch Diameter

Screw Identification Standard Thread Information 1/4 x 20 x 3. 0 NC Pitch Length in (TPI) Outside inches diameter of (Optional) screw shaft (inches) Thread description coarse or fine (Optional) Metric Thread Information M 3 x 0. 5 x 30 M = Metric Outside Pitch diameter of (mm per screw shaft thread) (mm) Length in mm (Optional)

Screw Identification Unified Thread Information #4 x 40 x 2. 0 NC Pitch Length in (TPI) Outside inches diameter of (Optional) screw shaft (inches) Thread description coarse or fine (Optional) • In Unified threads (measured in inches) there are numbered diameters #0 through #10 • #0 the smallest and #10 is the largest • The major diameter in Unified Threads = 0. 060" + 0. 013" X (numbered diameter) • Example: A #2 has a major diameter of 0. 086"

Screw IMA 1/4 20 NC DE = One rotation of the effort = Circumference DR = Linear distance traveled during one rotation = Pitch What is the IMA of the screw above if effort is applied by an 8. 0 in. long wrench?

Screw AMA 8 in. 1/4 20 NC 35 lb What is the AMA of the screw? AMA = 34. 29 = 34: 1 1200 lb What is the efficiency of the screw? Efficiency = Why is efficiency so low? = 0. 0341 or 3. 4%

Compound Machines Simple machines working in combination to complete a task Calculating mechanical advantage

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