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Name _______________________________
Date __________
Line _______
Machines help in 3 ways:
Two forces are involved when machines do work…
Mechanical Advantage
You pull a hammer with a force of 100 N and the hammer pulls a nail with a force
of 2000 N. What is the mechanical advantage?
Efficiency
To pull the nail out of the wood board, the carpenter does 1000 J of work. The hammer he uses
does 800 J of work. What is the efficiency of the hammer?
Where does the work go? _________________________________________________________
Name _________________________________________
Date ______________
1)
You apply a force of 18 N on to the end of a lever to open a can of paint. The lever’s force
on the lid is 9N. What is the mechanical advantage?
2)
A 1000 N force is applied to a crowbar to open a trunk. The crowbar puts a force of 2000 N
onto the lid. What is the mechanical advantage of the crowbar?
3)
A stage crew member uses a pulley system to lift scenery for a school play. He does 700 J
of work and the pulley system does 350 J of work. What is the efficiency of the pulley
system?
1)
A ramp is used to load furniture onto a moving truck. The person does 1250 J of work
pushing the furniture up the ramp and the ramp does 800 J of work. What is the efficiency of
the ramp?