Mechanical Advantage

Which of the following is an example of work being done?

• Teacher sitting in a chair
• Book resting on desk
• Keys hanging from a key chain
• A ball being rolled on the floor

Is this an example of work?
A teacher applies a force to a wall and becomes exhausted.

• True
• False

Is this an example of work? 
A waiter carries a tray full of meals above his head by one arm straight across the room at constant speed. 

• True
• False

What is the mechanical advantage of this pulley?

• .5

• 1

• 1.5

• 2

What is the mechanical advantage of this pulley system?

• 4

• 6

• 8

• 10

What is the mechanical advantage of the block and tackle used to lift the bale of cotton?

• 1
• 2
• 3
• 4

which is an inclined plane?

• pulley

• screw

• lever

• gear

How do you calculate the MA of an inclined plane?

• height / length
• input X  height
• length / height
• output X length

The THICKER the wedge, the greater its mechanical advantage.

• True
• False

The threads of a screw act like a(n)...

• Lever
• Wedge
• Inclined Plane
• Fulcrum