What is a Machine? Section 8.2 quiz

_____ ________ would be a machine that had 100% mechanical efficiency.

Ideal Machine

___________ _____________ is a number that shows how many times a machine multiplies force

Mechanical Advantage

_____________ ____________is a comparison of a machine's work output with the work input.

Mechanical Efficiency

In mechanical advantage, what does it mean if a number is more than one? What does it mean if the number is less than one?

More than one - the output force it greater and the machine can move/lift heavier objects Less than one - the output force is less, but the distance the object moves is greater *idk if the less than one is right. that is what it said on the document but people might have changed it.

The more times a machine multiplies the input force, the ____ the machine is.

better

Machines use lubricants, such as oil or grease, to lower the _______ between their moving parts, which makes the machines more efficient.

friction.

A machine with a MA >1 = output force is _______ than the input and the machine can lift/move heavy objects

greater

Force and Distance are ________ proportional

inversely

A machine that has a MA <1 = output force is ____, but the distance an object moves is greater

less

A ________ is a device that makes work easier by changing the size or direction of the force.

machine

is a device that makes work easier by changing the size or direction of a force

machine

The number of times the machine multiplies force

mechanical advantage

is a comparison of a machine's work output with the work input

mechanical efficiency

The work that you do on a machine

work input

The work done by the machine on an object

work output

True or False Mechanical efficiency is expressed in newtons.

False It is expressed in percentage

True or False Machines make work harder by changing the size and/or direction of the input force, but the amount of work does not change

False Machines make work easier

True or False All of the work done by the machine is used to overcome the friction created by the use of the machine.

False Only some of the work done by the machine is used to overcome friction.

True or False As a machine changes the size of a force, the machine doesn't change the distance through which the force is applied

False The machine does change the distance through which the force is applied.

True or False Work output is always greater than work input.

False Work output is never greater than work input

What is the mechanical efficiency equation?

ME = Work Output / Work Input x 100

True or False Ideal Machines are impossible to build because every machine has moving parts which creates friction.

True

True or False Machines allow force to be applied over a greater distance, which means that less force will be needed for the same amount of work

True

True or False The less friction the machine has to overcome, the more mechanical efficiency.

True

True or False Work is done when a force is applied through a distance

True

What is the WO, WI, IF, and OF of someone jacking up a car?

WO - the car pushing up WI - the lever pushing the car *idk what the IF and OF is. i think someone deleted it. make sure you know what is for the test.