Question

Question 8: A pulley of diameter 40 mm rotating at 60 rpm drives the another pulley of diameter 80 mm. What is the speed of driven pulley if 5% slip in the belt present? O 28.5 rpm​

Answer 1

Given :-

A driving pulley having diameter of 40mm(D1) rotating at speed (N1) of 60rpm and it drives another pulley which have diameter(D2) of 80mm. It is also given that the 5% slip occurs in the belt.

To Find:-

The speed of the driven pulley i.e. let say N2

Solution:-

We have the expression for finding the speed of the driven pulley

=> N2/N1 = D1/D2 [1-S/100]

where , N1= speed of the driving pulley

          N2= speed of the driven pulley

            D1= diameter of the driving pulley

        D2 = diameter of the driven pulley

And ,  S = slip of the belt

Now on putting all the values in the above expression we get

=>    N2/60 = 40/80 [1- 5/100]

=>    N2 =  3*9.5

=>   N2= 28.5 rpm

So the speed of the driven pulley is 28.5 rpm  i.e. the required answer