Answer
(a) $1.06\times 10^3Kg$
(b) $932Kg$
Work Step by Step
(a) The total load supported by the springs can be calculated as
$T=2\pi\sqrt{\frac{M+m}{K}}$
This can be rearranged as:
$M+m=(\frac{T}{2\pi})^2K$
$M+m=(\frac{1.65}{2\pi})(1.53\times 10^4)=1057Kg=1.06\times 10^3Kg$
(b) The mass of the car is given as
$M=(M+m)-m$
We plug in the known values to obtain:
$M=1057-125=932Kg$
