6.3 Guided Notes: Simple Machines

What is a machine?

• A device with moving parts that work together to accomplish a task.
• A form of energy that comes from force applied over distance.
• A contraption that can neither be created or destroyed.
• Option 4

Is a bicycle an example of a machine?

• yes
• No

Which word identifies everything you do to make a machine work?

• input
• output

Which word identifies what a machine does for you?

• input
• output

A simple machine is an unpowered mechanical device that accomplishes a task with only one movement. Identify which of the following are simple machines that work with forces. Check each one that applies.

• wheel and axle
• rope and pulleys
• ramp
• gears
• lever

According to the text, what factor prevents any machine from being considered perfect?

• friction
• size
• gravity
• weight

A rule that is true for all machines is that the output work can never be greater than the input work.

• True
• False

What is efficiency.

• forces, energy, or power supplied to make a machine work
• the forces , energy or power provided by the machine
• the ratio of output force divided by input force
• the ratio of output work divided by input work

What unit is typically used to express efficiency?

• percentages
• decimals
• fractions

Levers include a stiff structure that rotates around a fixed point. What is this fixed point called? Write your answer below using all lowercase letters. Spelling counts!