14.4 quiz
What determines the ideal mechanical advantage of a pulley or pulley system?
It is equal to the number of rope sections supporting the load being lifted
All classes of levers...
are used to make a load easier; all have a fulcrum, input force, and output force; and all have a IMA found by diving the input force by output force.
Circle the letter of the sentence that describes how to calculate the IMA of a wheel and axle. a. Multiply the area of the wheel by the area of the axle. b. Divide input force by output force. c. Divide the diameter where input force is exerted by the diameter where output force is exerted. d. Divide the radius of the wheel by the force exerted on it.
c
A simple machine consisting of a rope fitted into a groove in a wheel is a(n) __________________ .
pulley
what are these examples of? wheelbarrow, nutcracker
second class lever
in a 1st class lever...
the fulcrum is between the input force and output force, IMA can be less than one, greater than one, or = to 1
in a 3rd class lever...
the input force is between the output force and fulcrum, the IMA is always less than one
in a 2nd class lever...
the load is between the fulcrum and the input force, the IMA is always greater than one
what are these examples of? tweezers, arm, baseball bats, hockey sticks, golf clubs, fishing, unattached oar, someone sweeping, stapler, tongs
third class lever
T or F? First class levers always have a mechanical advantage that is greater than 1.
false; it can be greater than 1, equal to 1, or less than 1
what are these examples of? screwdriver used to open a can, seesaw, scissors, oars on a boat with rings, crow bar
first class lever
Screws with threads that are close together have a greater________________________________
ideal mechanical advantage (IMA)
the mechanical advantage of a machine in the absence of friction is...
ideal mechanical advantage (IMA)
A slanted surface along which a force moves an object to a different elevation is called a(n) ______________
inclined plane
the distance between the fulcrum in a lever and the input force
input arm
the force exerted ON a machine
input force
a fulcrum is related to a lever because....
it is the point at which the lever moves around; it helps the lever lift things; depending on where you place it, there are different levers than can be made
a screwdriver used to pry the lid off a paint can is an example of a__________
lever
what do you use to pry/ lift things?
lever
what is a rigid bar that is free to move around a fixed point (fulcrum)
lever
list the 6 types of simple machines
lever, wedge, wheel and axle, inclined plane, screw, pulley
the distance between the fulcrum in a lever and the output force
output arm
to calculate the ideal mechanical advantage of any lever, divide the input arm by the____________
output arm
the force exerted BY a machine
output force
a simple machine that consists of two disks or cylinders, each with a different radius that rotate around each other
wheel and axle
what characteristics distinguish levers as 1st class, 2nd class, or 3rd class?
where the fulcrum, input arm, and output arm is are located
Circle each letter that identifies a compound machine. a. a car b. a handheld screwdriver c. a washing machine d. a watch
a, c, d
the fixed point that a lever rotates around is called the____________
fulcrum
A thin wedge of a given length has a(n) ________________ advantage than a thick wedge of the same length.
greater
Is the following sentence true or false? A compound machine is a combination of two or more simple machines that operate together.
true
Is the following sentence true or false? The ideal mechanical advantage of an inclined plane is the distance along the incline plane divided by its change in height.
true
T or F? All second-class levers have a mechanical advantage greater than one because the input arm is longer than the output arm
true
