your front teeth can act as a simple machine. which machine are they?; what is the amount of strength that is applied to the rope in a pulley to raise the object called?; the wheel and axle is an example of a/an _________.; which simple machine is a doorknob? a lever a screw a pulley a wheel and axle; which simple machine is the lid of a jar?a levera screwan inclined planea wheel and axle; what is the factor by which a simple machine multiplies the strength put into a machine called?; who invented a very efficient lubricating device for trains?; trisha works for a roofing company