Sixth meeting (Tuesday, February 23)

Done!!!

Completed Machine

Calculating...

Weights

Final touches...

Fulcrum

    We brought our completed nifty lifting machine to school, and we started experimenting with how much input force it required to lift the output force, 600g, up 5 cm to find the actual mechanical advantage. We carefully placed colored pencils in the input force can, and as a result, we found that 103g was needed to complete work. These are the calculations we did:

Actual Mechanical Advantage = Output force divided by Input force
600g (Output force) divided by 50g (Input force) = 12

Actual Mechanical Advantage of our nifty lifting machine: 12

    Next, we wanted to find the ideal mechanical advantage of our machine. We measured the distance from the fulcrum to the input and output force for our lever. These are the calculations we did:

-Ideal Mechanical Advantage = the product of the mechanical advantages of every simple machine

-Mechanical Advantage of a block and tackle pulley = 3

-Mechanical Advantage of a lever = distance from fulcrum to input force divided by distance from fulcrum to output force
-Distance from fulcrum to input force- 83 cm
-Distance from fulcrum to output force- 18 cm
-83 divided by 18 = about 4.6

3(Mechanical advantage of block and tackle pulley) x 4.6  (mechanical advantage of lever) = 13.8

Ideal Mechanical Advantage of our nifty lifting machine: 13.8

    If we compare the actual mechanical advantage of 12 and the ideal mechanical advantage of 13.8, we can see how much effect friction has on our machine. A way to show this is through efficiency. To calculate efficiency ;

Efficiency = actual mechanical advantage divided by ideal mechanical advantage x 100

12 divided by 13.8 x 100 = about 87%

      The efficiency of a machine shows how much friction is lost, and we can see that 13% of the efficiency is lost due to friction.
      We are extremely satisfied with the outcome of our machine and our high mechanical advantages, and after four different designs, we are finally done with our machine. Yaaaaaay!!!!