Abar 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

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

The speed was not exceeded so it was slow