A load of 1000 N is lifted with the help of a first class lever and the effort applied to do the work is as mentioned in the table below. Calculate...

Hello!

A lever is a simple machine (one of the simplest and long known). It consists of something long and firm, and a fulcrum on which to rotate. A first class lever have the fulcrum between the load and the effort.

A lever gives us a mechanical advantage in force if the effort arm is longer than the load arm. And it gives an advantage in displacement otherwise. But nothing comes free, and an advantage in force means the same loss in displacement and vice versa (if no friction is assumed).

I suppose that the table shows efforts in the second row and the corresponding effort arms in the first row, while the load arm remains constant. The law of the lever says that the product of an effort and its arm is a constant.

Therefore

`800*10 = a*20 = b*30 = 600*c = d*50.`

Now we can find the unknowns easily:

`a=(800*10)/20=800/2=400 (N),`
`b=(800*10)/30 approx 266.7 (N),`
`c=(800*10)/600 approx 13.3 (cm),`
`d=(800*10)/50 = 160(N).`