After completing the first Lever Lab in class, you will have noticed that your basic 3rd class lever is terrible in terms of how much effort you need to put into the lever to move a load! Many of you noticed you had to use at least twice the force in Newtons. (Using 11N of Effort, to lift a 5N load) The second class lever seemed the best, allowing you to lift 5N using only 4N of effort. That's a nice little advantage!
This is where the term: Mechanical Advantage comes in.
MECHANICAL ADVANTAGE is the amount of extra FORCE (N) a machine can give you. You calculate Mechanical Advantage (M.A.) by dividing the LOAD (Output) by the EFFORT (Input)
M.A. = Load (N)
Effort (N)
So using the example from the lab:
1st class lever: MA = 5N/5N = 1
2nd class lever: MA = 5N/4N = 1.25
3rd class lever: MA = 5N/11N = 0.45
From these numbers we can make some general statements:
If MA = 1, we get .........
If MA > 1, we get ..........
If MA < 1, we get ..........
REMEMBER THAT WE NEVER GET ANYTHING FOR FREE! WHAT IS THE TRADE OFF WHEN WE GET A FORCE ADVANTAGE IN A MACHINE THAT ALLOWS US TO LIFT MORE THAN THE EFFORT WE PUT IN (LIKE IN THE 2ND CLASS LEVER)?????
This is where the term: Mechanical Advantage comes in.
MECHANICAL ADVANTAGE is the amount of extra FORCE (N) a machine can give you. You calculate Mechanical Advantage (M.A.) by dividing the LOAD (Output) by the EFFORT (Input)
M.A. = Load (N)
Effort (N)
So using the example from the lab:
1st class lever: MA = 5N/5N = 1
2nd class lever: MA = 5N/4N = 1.25
3rd class lever: MA = 5N/11N = 0.45
From these numbers we can make some general statements:
If MA = 1, we get .........
If MA > 1, we get ..........
If MA < 1, we get ..........
REMEMBER THAT WE NEVER GET ANYTHING FOR FREE! WHAT IS THE TRADE OFF WHEN WE GET A FORCE ADVANTAGE IN A MACHINE THAT ALLOWS US TO LIFT MORE THAN THE EFFORT WE PUT IN (LIKE IN THE 2ND CLASS LEVER)?????