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Section 1 Continue What is power? Power is the rate at which work is done. How do you calculate power? Power = work/time or power = (force X Distance)/time
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Review of Chapter 4Review of Chapter 4Book “M”
Section 1Section 1What is work?Work is done on an object when
the object moves in the same direction in which the force is exerted.
How do you find work?Work = Force X Distance
Section 1 Continue Section 1 Continue What is power?Power is the rate at which work is
done.How do you calculate power?Power = work/time or power =
(force X Distance)/time
Section 2Section 2What is a machine?Machine is a device that allows you to
do work in a way that is easier or more effective
What is input force?The force you exerts on the machine.
Also know as the effort forceWhat is the output force?The force the machine exerts on an
object. Also know as the resistant force
Section 2 ContinueSection 2 ContinueWhat is input work?Input force time the input distanceWhat is output work?Output force time the output
distanceWhat are the three ways a
machine can make work easier?Changing force, changing
distance, and changing direction
Section 2 ContinueSection 2 ContinueWhat is Mechanical Advantage?A comparison of the input force
to the output force or the number of times a machine increases a force exerted on it.
How do you find?MA = output force/input force
Section 2 ContinueSection 2 Continue What is efficiency?The efficiency of a machine compares the
output work to the input work.How do you find efficiency?Efficiency = (output work/input work) X
100%What is the difference between ideal and
real machines?Ideal machines have 100% efficiency and
only exist on paper, and real machines lose some work due to friction, thus always having less than 100% efficiency.
Section 3Section 3What are the 6 basic kinds of simple
machines?Inclined plane, wedge, screw, lever,
wheel and axle, and pulleyWhat is an incline plane?Incline plane is a flat, sloped surfaceWhat is the ideal mechanical
advantage of an incline plane?IMA = length of incline/height of
incline
Section 3 continueSection 3 continueWhat is a wedge?A device that is thick at one end and
tapers to a thin edge at the other endHow do you find the mechanical
advantage?IMA = Length/widthWhat is a screw?A screw can be thought of as an incline
plane wrapped around a cylinderHow do you find the mechanical
advantage of a screw?IMA = length around the threads/length
of the screw
Section 3 continueSection 3 continueWhat is a lever?A rigid bar that is free to pivot, or
rotate, on a fixed pointWhat are the three types?First-class, second-class, and third-
classHow do you find the mechanical
advantage of a lever?IMA = distance from fulcrum to input
force(or effort distance)/Distance from fulcrum to output force(or resistant distance)
Section 3 continueSection 3 continueWhat is a wheel and axle?A simple machine made of two
circular or cylindrical objects fastened together that rotate about a common axis.
How do you find the mechanical advantage?
MA = radius of wheel/radius of axis
Section 3 continueSection 3 continueWhat is a pulley?A simple machine made of a grooved
wheel with a rope or cable wrapped around it.
What are the three types?Fixed pulley, movable pulley, and
block and tackleWhat is the mechanical advantage?IMA = number of sections of rope that
support the object.
Section 3 continueSection 3 continueWhat is a complex machine?A machine that utilizes two or
more simple machinesHow do you calculate the
mechanical advantage?IMA = the product of the
individual IMA of simple machines that make it up.