Classes of Levers: More Practice. 3 rd class lever.

Classes of Levers: More Practice

Classes of Levers: More Practice

3rd class lever

Classes of Levers: More Practice

Classes of Levers: More Practice

1st class lever (x2)

Classes of Levers: More Practice

Classes of Levers: More Practice

2nd class lever

Classes of Levers: More Practice

Classes of Levers: More Practice

2nd class lever (x2)

Classes of Levers: More Practice

Classes of Levers: More Practice

1st class lever

Classes of Levers: More Practice

Classes of Levers: More Practice

3rd class lever (x2)

Classes of Levers: More Practice

Classes of Levers: More Practice

Classes of Levers: More Practice

Pulleys and Pulley Systems: Student Learning GoalThe student will be able to construct a system of

pulleys and determine its ideal and actual mechanical advantage (C2.7).

Pulleys and Pulley Systems

SPH4C

The Pulley

The pulley is a member of the lever family because it is a rigid object that can rotate freely around a fulcrum.

The wheel has a grooved rim in which a rope or cable can run.

A Single Fixed Pulley

A single fixed pulley (in which the fulcrum does not move) gives no mechanical advantage but changes the direction of the effort force (FE) required to lift the load force (FL).

A Single Movable Pulley

A pulley in which the fulcrum does move when the load is moved is called a moveable pulley.

There is a mechanical advantage to using this pulley.

Pulley Systems

A system of pulleys can also give you a mechanical advantage.

Pulley Systems

A system of pulleys can also give you a mechanical advantage.

The IMA will be equal to the number of support strands (i.e. strands pulling upward). This system of one

fixed pulley and one moveable pulley has 2 support strands.

Moveable Pulley: Example

What is the IMA of a single moveable pulley?

Moveable Pulley: Example

What is the IMA of a single moveable pulley?

IMA = 2

Pulley Systems: Example

What is the IMA of the pulley system at right?

Pulley Systems: Example

What is the IMA of the pulley system at right?

IMA = 3

Pulley Systems: Example

What is the IMA of the pulley system at right?

IMA = 3

Pulley Systems: Example

What is the IMA of the pulley system at right?

IMA = 3So you would expect the FE

to be three times less than the FL . . .

Pulley Systems: Example

What is the IMA of the pulley system at right?

IMA = 3So you would expect the FE

to be three times less than the FL . . .

But friction, the mass of the pulleys, etc. will increase your required FE .

More Practice

Pulley Systems Lab Activity