Work
What is the SI unit of work?
Joule
What is a machine?
A device that changes a force and makes work easier.
What is the SI unit of power?
Watts
Why can no machine be 100% efficient?
Because of the friction acting on the machine.
What is the formula to find work?
Force x Distance = Work
What is work?
The product of force and distance.
What are the 6 types of simple machines?
Lever, Wheel and Axle, Inclined Plane, Wedge, Screw, Pulley
How many watts are equal to one horsepower?
746 watts = 1 horsepower
What is Ideal Mechanical Advantage (IMA)?
The mechanical advantage of a machine in the absence of friction.
What is the formula to find power?
Work ÷ Time = Power
What must happen for a force to do work on an object?
Some of the force must act in the same direction as the object moves.
The force exerted on a machine is called what?
The input force.
What is power?
The rate at which work is done.
What is Mechanical Advantage?
The number of times a machine increases an input force.
What is the formula to find efficiency?
Work output ÷ Work input x 100% = Efficiency
True or False.
A weight lifter does no work on the barbell as he holds it over his head.
True.
How do machines make work easier?
By changing the size of a force needed, the direction of a force, or a distance over which a force acts.
True or False
Doing work at a faster rate requires more power.
True.
What is Actual Mechanical Advantage (AMA)?
The mechanical advantage of a machine in the presences of friction.
What is the formula to find Ideal Mechanical Advantage (IMA)?
Input distance ÷ Output distance = (IMA)
What is the only way to increase work output?
By increasing the amount of work put into the machine.
Fill in the blank.
Due to _________ the work done by a machine is always less than the work done on the machine.
When using SI units in the power formula, what is the time measured in?
Seconds
What is efficiency?
The percentage of the work input that becomes the work output.
What is the formula to find Actual Mechanical Advantage (AMA)?
Output force ÷ input force = (AMA)