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