Work and Machines study guide

The following texts are the property of their respective authors and we thank them for giving us the opportunity to share for free to students, teachers and users of the Web their texts will used only for illustrative educational and scientific purposes only.

All the information in our site are given for nonprofit educational purposes

The information of medicine and health contained in the site are of a general nature and purpose which is purely informative and for this reason may not replace in any case, the council of a doctor or a qualified entity legally to the profession.

Work and Machines study guide

POWER is the rate at which work is done.
If tight scissors have an efficiency of 50%, half of your work is wasted due to FRICTION
Most of the machines in your body consist of bones and muscles and are called LEVERS
A simple machine that might be thought of as an inclined plane that moves is a WEDGE
An incisor is what type of simple machine? WEDGE
An ideal machine would have an efficiency of 100 %
For WORK to be done on an object, the object must move some distance as a result of a FORCE
Without FRICTION there would be equal input and output work.
Holding a 25 N bag of sugar 1 meter above the floor requires 0 joules of work.
Power is measure in units called WATTS
WORK equals force times distance.
A hockey stick is considered a machine because it multiplies the DISTANCE
A fishing pole is an example of a 3RD class lever.
A bicycle is an example of a COMPOUND machine.
WORK is measured in Joules.
Pulling down on a rope to hoist a sail on a sailboat is an example of a machine changing DIRECTION over which a force is exerted.
You do WORK on an object when you lift it from the floor to a shelf.
The force exerted by a machine is called the OUTPUT force.
The fixed point that a lever pivots around is called the FULCRUM
The MA of a machine that changes only the direction of force is 1 (ONE)
A machine that utilizes two or more simple machines is called a COMPOUND machine.
A ramp is an example of a simple machine called an INCLINED plane.
The body part that is shaped like a wedge would be your INCISORS
If you exert a force of 50 N to push a desk 10 meters, how much work did you do? 500 JUOLES
The mechanical advantage of a machine is the number of times a MACHINE increases the force exerted on a machine.
A wheel and axle is a SIMPLE machine.
The wedge, screw and lever are all SIMPLE machines.
When you raise and lower a flag on a flagpole, you are using which simple machine? PULLEY
Machines change the amount of FORCE you exert or the DISTANCE over which you exert the force.
The ideal mechanical advantage for an inclined plane is equal to the length of the incline divided by the HEIGHT OF THE INCLINE
The ideal mechanical advantage of a WHEEL AND AXLE is equal to the radius of the wheel divided by the radius of the axle.
A SCREW is an inclined wrapped around a cylinder.
In order to do work on an object, the force you exert must be in the same DIRECTION as the object’s motion.
The power of a light bulb that converts electrical energy at a rage of 100 joules per second is 100 watts.
The MA of a machine that changes only the direction of a force is 1 (ONE)
EFFICIENCY compares the output work to the input work.
A second class lever always multiplies FORCE
The ideal MA of a wheel and axle is the RADIUS of the wheel divided by the RADIUS of the axle.
When you raise your leg, the HIP acts as a fulcrum for the upper leg.
What class of lever is a fishing pole? 3RD wheelbarrow? 2ND bottle opener 2ND pliers? 1ST
Scissors are what class of lever? 1ST why? THE FULCRUM IS BETWEEN THE INPUT FORCE AND THE OUTPUT FORCE
Study the drawings of the classes of levers.
Know when the Mechanical Advantage of a machine is greater than one and less than one.

Source : http://kokonkwo.weebly.com/uploads/1/3/2/1/13217879/work_and_machines_study_guide_key.doc

Web site link to visit: http://kokonkwo.weebly.com

Google key word : Work and Machines study guide file type : doc

Author : not indicated on the source document of the above text

If you are the author of the text above and you not agree to share your knowledge for teaching, research, scholarship (for fair use as indicated in the United States copyrigh low) please send us an e-mail and we will remove your text quickly.