Solving a Lever System Problem: Force, Fulcrum, & Equilibrium

[MACHO-WIMP]

The problem in my packet says, "A medical technician uses a pair of four inch longtweezers to remove a wood sliver from a patient. The technician is applying one pound of squeezing force to the tweezers. If more than 1/5 lb of force is applied to the silver, it will break and become difficult to remove.

a. Sketch and annotate the lever system described above.
b. What is the actual mechanical advantage of the system?
c. Using static equilibrium calculations, calculate how far from the fulcrum the tweezers must be held to avoid damaging the sliver. "

I don't understand how this problem can be done or if there is enough information to solve.

 

[Doc Al]

Hint: Tweezers can be considered a kind of lever. (Actually a pair of levers.) Where's the fulcrum?

 

[MACHO-WIMP]

I know it's two 3rd class levers, but I don't think there is enough information to solve, because it doesn't say where the pound of force is applied

 

[Doc Al]

I know it's two 3rd class levers, but I don't think there is enough information to solve, because it doesn't say where the pound of force is applied

You should be able to figure where it's applied, so as to produce a 1/5 pound force at the tips. Make the assumption that the technician wants to apply exactly that much force to the sliver. (Though it's true that it doesn't state that.)

 

[MACHO-WIMP]

So would the 1/5 lb of force be considered the resistance force?

 

[Doc Al]

So would the 1/5 lb of force be considered the resistance force?

Yes, the load or resistance force.

 

[MACHO-WIMP]

If my math is right, I got AMA=1/5 and the distance needed to be held is 4/5 of an inch. Does that sound about right?

 

[Doc Al]

If my math is right, I got AMA=1/5 and the distance needed to be held is 4/5 of an inch. Does that sound about right?

Sounds good to me.

 

[MACHO-WIMP]

Sounds good to me.

Thanks a lot man. You were a big help.