
K is corresponding spring constant for a wire for easing the calculation using F=-kx
Y is young's modulus of elasticity.





Simply all conditions have been incorporated in the standard formula.
As a convention u is taken -ve for real object. In this case as object and image are opposute side of the mirror so for -ve u the v is taken as +ve.

First change RPM to radian per second by using definition formula of angular speed (omega)

lost 10% so remaining is 90 % which means ME2= (90/100) multiplied by ME1

