Question

A bar is used to lift a 100-kg block of concrete. The pivot is 1.00m from the block. (a) If the worker pushes down on the other end of the bar a distance of 2.50m from the pivot, what force (in N) must the worker apply? (b) Find the MA

Answer 1

a) From, the principle of moments the clockwise moment is equal to the anticlockwise moments.
 weight of the block × distance from the pivot = Force × distance to the pivot
= 1000× 1 = 2.5 × F
= 2.5 F = 1000
       F =  400 N

b) IMA is an ideal machine's mechanical advantage. They are calculated by dividing the distance over which you apply effort by the distance moved by the load.
In this case; 
IMA = 2.5/1
       = 2.5
The IMA is therefore 2.5