CK-12 Physical Science Concepts - For Middle School

http://www.ck12.org Chapter 4. Motion and Forces

http://www.walter-fendt.de/ph14e/pulleysystem.htm

Q: Which type of pulley is the old pulley in the opening image?

A: The old pulley is a single fixed pulley. It is securely attached to the beam above it.

TABLE4.4: Pulleys

Type of Pulley How It Works Example No. of Rope

Segments

Pulling Up

Ideal Mechani-

cal Advantage

Change in

Direction of

Force?

Single fixed pul-

ley

Flagpole pulley 1 1 yes

Single

moveable

pulley

Zip-line pulley 2 2 no

Compound

pulley (fixed

& moveable

pulleys)

Crane pulley ≥ 2 ≥ 2 varies