Mechanical Systems - Simple Machines

Past and Present Machines

100

Machines with many parts that involve more than one simple machine are called

complex machines

200

Before vehicles were invented, people would travel long distances using this

horse and carriage 

300

People used to fetch water from a well, using this simple machine to lower and raise a bucket

pulley

400

This scientist said "give me a lever long enough and a fulcrum on which to place it, and I shall move the world"

Archimedes

500

Simple machines change the ________ and/or ________ of a force

direction

magnitude

Identify the Simple Machine

100

A twist off jar lid is an example of this simple machine

screw

200

A ramp is an example of this simple machine

inclined plane

300

A zipper is an example of this simple machine

wedge

400

A wheelbarrow is comprised of these two simple machines

lever and wheel and axle 

500

A shovel is comprised of these two simple machines

lever and wedge

Vocabulary

100

The point on which a lever rests and pivots on

fulcrum

200

How effective a machine is at converting input energy to output energy

efficiency 

300

The center point which a wheel and axle rotate about

axis

400

The ratio of output force to input force in a mechanical system

mechanical advantage

500

A group of two or more gears

gear train

Applications of Simple Machines

100

Which has a higher mechanical advantage: fixed pulley or moveable pulley?

moveable pulley

200

A screw is a simple machine that is really a ________ wrapped around a cylinder

inclined plane

300

Which simple machine is more efficient - inclined plane or pulley?

pulley

400

This class of lever gives the most mechanical advantage

class 2

500

Name 3 things a wedge can do

Cut, split, scrape, tighten and hold back, hold together

Formulas

100

If work remains the same and distance is decreased what happens to the force?

increases

200

Another way to calculate mechanical advantage of a lever in addition to output force / input force is length of __________ / length of _________

effort arm

load arm

300

For a higher speed ratio, you would want a follower gear with more or less teeth?

less

400

How do you find the mechanical advantage of a wheel and axle?

radius of wheel / radius of axle 

500

Which is more efficient:

1) a pulley system that has an output energy of 2J with an input energy of 10J

2) a lever that has an output energy of 2J with an input energy of 20J

1) a pulley system that has an output energy of 2J with an input energy of 10J