### implement | bar:

Error bar
* account for photometric errors and uncertainties in the sky level.
* are about the size of the data points
  - bootstrapped standard errors on the population mean
  - inversely proportional to the number of pulsar products averaged
  - one standard error of the mean
  - probable errors in the mean
* are the fluctuation levels calculated from the simulated halos
  - standard deviation of the average
  - twice the standard error of the mean averaged over about a month of comparative data
* correspond to the standard error of the mean.
* indicate deviation
* represent standard deviations of the data that was averaged
  - error of measurement
  - errors of the mean

Grab bar
* are bars.
* come in metal or plastic and in many sizes and colors.
* help people remain active and less dependent on assistance from others.

Gray bar
* indicate climate transitions based on shifts in accumulation rate
  - in gray scale and light laminae thickness
* represent the yearly sum of precipitation.
* represents melting point and freezing point of wood frogs.

Handlebar
* Some handlebars are part of bicycles
  - bikes
  - handles
* includes handles
  - sections

### implement | bar | handlebar:

Bicycle handlebar
* can act as blunt spears and cause the injuries on impact.
* make steering much easier than steering a canoe.

### implement | bar:

Lever
* Most levers transmit forces
  - muscular forces
* Some levers have the fulcrum between the effort and the load, as in crowbars and scissors.
* amplify force and energy
  - or increase the force or velocity of motion
* are bars
  - devices
  - machines
  - one of the very first machines that humans developed
* are rigid bars that rotate about a pivot called a fulcrum
  - rods that can be moved about a fixed point
  - tools
  - tumblers
* have a straight part that moves when a force is applied to it.
* help to lift loads with less effort.
* includes fulcrums
  - sections
* involve the idea of rotational motion.

### implement | bar | lever:

Crowbar
* Some crowbars have a notched an end for removing nails.
  * Man using a long crowbar to remove a board. A 'crowbar' metal tool used mainly to pry things open. It is usually hook shaped. Sometimes the bottom is slightly curved to allow for better leverage. Some crowbars have a notched an end for removing nails. Crowbars are often made of carbon steel. They can also be made of titanium which is lighter and non-magnetic. The first known use of the word was somewhere in the 1400s where they were simply called crows or iron crows.
* are industrial equipment
  - located in cabinets
  - tools

Foot pedal
* can lead to leg strain.
* help to avoid such awkward positions.

Joystick
* are another input device and often make playing computer games easier and more fun
  - control
  - handheld devices which enable simultaneous analog control for multiple axes
  - input devices
  - one simpliest pieces of computer equipment
* help to recreate reality.
* use more arm movement and less wrist movement.
* vary in size and have a stick-like figure stemming from a base.

Nutcracker
* are located in stores
  - unusual corvids having considerable amounts of brown in their colouration
* bury caches of nuts in loose soil on the mountainside.
* caches the seeds in microclimates conducive to germination.
  - sections
* normally bury nuts further up hill than they collect.

Pedal
* Some pedals are part of bicycles
  - motorbikes
* are control devices
* are located in cars
  - pianos
  - motor vehicles
  - organs
* includes fulcrums