IMA 5 Lever

[rfelton]

I am trying to coach kids in science olympiad and hate to disappointment them. I attached a file. I need to use to class of levers in conjunction to create an IMA of 5. Is the attached photo correct? Thanks for any help you can give.

[efzauner]

the mechanical advantage is always the ratio of the distance between the forces and the fulcrum.

In the left hand section, it is a class 1 lever with the advantage being 20/10= 2.

In the right hand section, it is a class 2 lever with the mechanical advantage being 21.5/8.5 = 2.5 I am assuming that the 21.5cm distance is from the force to the fulcrum and NOT the force to the load. This is often a mistake in interpreting or drawing the distance. Is the lenght of the bar 21.5cm or 21.5+8.5 cm? In this case I am assuming it is 21.5cm

 

so the total advantage is 2 x 2.5 =5

[rfelton]

Thank you for your reply! The total length of the bar turned out to be 29 cm. the distance from the load to the force is 21.5 and the distance from the force to the fulcrum is 7.5. I may have not done the math correct. so in theory for the class 2 lever if the over all length was 30 cm then the length from load to fulcrum would be 12 and the distance from force to load would be 18. is that correct?

[efzauner]

then for the lever on the right side,

distance from force to fulcrum is 29

distance from load to fulcrum is 7.5

the force advantage is 29/7.5

 

 

for the secod question correct ,but dont confuse people Draw always the lenghts from force or load to fulcrum!

Force to fulcrum =30 load to fulcrum =12 advangtage is 30/12 =2.

[Hoosier12]

I am working on the same figure as above. I am stuck on the fact that does the amount of each load matter in calculating an IMA of greater than 5? I know the equations only involve distances between the force/load to fulcrum, but I see no mass in the calculations and I feel it should I guess? I am trying to combine two different classes of levers into a system with an IMA > 5. To get the total do you multiple the two IMA's of each lever? Thanks for your help! I am stuck!!!