Engraving Quiz

Mechanical Advantage (MA)

the ratio of the force produced by a machine to the force applied to it, used in assessing the performance of a machine.

Wedge

—Shovel

—Knife

—Saw

—Scissors

—Nail

—Basically two inclined planes (IP) connected

—Functions as moving IP

wedge (2)

Equation for wedge

—Height of wedge/Width of wedge face

H / F

Lever

—See Saw

—Crowbar

—Hammer pulling nail

—Diving Board

—Wheelbarrow

—Beam (LEVER ARM) supported

by pivot point (FULCRUM)

Force applied (EFFORT) to overcome

a load (RESISTANCE)

•Mechanical Advantage

MA=  De/Dr or R/E

Lever Formula

R x Dr= E x De

Which lever is this (see saw)

First class lever

Which lever is this (wheelbarrow)

2nd class lever

Which lever is this (baseball bat)

Third Class lever

Dr

distance to the resistance

De

Distance to the effort

R

resistance

e

effort

Pulleys

—Blinds

—Flag Pole

—Gym Equipment

—Cranes

—Sailboats

—Garage doors

Pulley

—is basically a wheel with a groove in the circumference of the wheel, with a belt or cable being fed around the groove.

driver

effort 1

MA for pulley

MA =     Follower Diameter/Driver Diameter

             

To find mechanical advantage of these systems, you will need one of the following variables:

—Diameter, torque, or rotational velocity

—Mechanical Advantage = Variable _output /Variable_input

Fixed fully systems

—Provides change of motion, but no mechanical advantage

follower

resistance 2

Movable pulley

—Provides change of direction and a mechanical advantage (at the expense of having to increase the amount of line to pull)

Mechanical Advantage of Moving Pulley Systems

—To calculate the mechanical advantage of a moving pulley system, you need to count the number of strings between moving pulleys ONLY

—You do not count the strings that are used to change direction.

Inclined Planes

—Wheelchair ramps

—Loading ramps for trucks

—Stairs

—Ladders

—Waterslides

MA for inclined plane

length/height

Screws

—This simple machine is simply an inclined plane wrapped around an axis

—It is a way of transferring motion from one position to another along an axis

—It can also be used to fasten things together