Question $1[7$ marks$]$

A shaft carries four small rotors A$,$ B$,$ C and D of mass $200Kg,350Kg,600Kg$ and $150$ Kg respectively. The radius of

rotation of the rotors are $75mm,60mm,80mm$ and $70$ mm respectively. The angles between the cranks

measured anti clockwise are A to B $45,B$ to $C70$ and C to $D120.$ The balancing masses are to be placed in

planes $x$ and $Y.$ The distance between the planes A and $x$ is $200$ mm ; between $x$ and $Y$ is $500$ mm ; between $Y$ and

$D$ is $250$ mm ; between A and $B$ is $300$ mm ; between $B$ and $C$ is $100$ mm $.$ If the balancing masses revolve at a radius

of $250$ mm $,$ find their magnitudes and angular positions.

Use of graphical method $(3$ marks$)$; Step wise solving for Magnitudes$-2$ marks; Step wise solving for angular

positions $-2$ marks

Formula: Centrifugal force $(Fc)=M^{*}r$ and Couple $(Mc)=M^{*}r*$ I