Six Simple Machines Lever Wheel Axle Pulley Inclined

Six Simple Machines – Lever – Wheel & Axle – Pulley – Inclined Plane – Wedge – Screw Part 2

Key Terms

The Inclined Plane

Geometry and Definitions L B H E A R

Formulas for Inclined Planes L E B MA = H A R

Inclined Plane Problem 1 Given the diagram as shown, if L equals 12 inches, H equals 3 inches and the effort is 30 pounds, find the mechanical advantage and the maximum load that can be moved. What is the tradeoff for reducing the effort? L E A B H R

Inclined Plane Problem 1, solution L E A B H R

Wedge

Inclined Plane vs. Wedge Effort Inclined Plane Wedge

Shape of Wedges L L H H Single Double

Formulas for Wedges MA = L L H Single H Double

Wedge Problem 1 Find the mechanical advantage and the maximum separation load for a wedge with an incline length of 10 inches, an overall height of 4 inches, and which is exerting an effort of 100 pounds. L H

Wedge Problem 1, solution Effort MA =

Screw

Screw Thread Classifications 1/4 - 20 UNC 1/4 is the outer diameter of the threads. 20 is the number of threads per inch of screw length. UNC refers to Unified National Coarse thread.

Screw Definitions Number of Threads per Inch OD 1 in. View A Pitch View A

Screw Pitch = Number of Threads per Inch 1 in.

Screw Formulas MA =

Screw Problem 1 A screw with 20 threads per inch is turned by a screwdriver having a handle diameter of 1 inch. What is the mechanical advantage of the screw? MA =

Screw Problem 1, Solution Circumference = Pitch = MA =