Answer
a) $x=0.049m$
b) $x=3.72m$
Work Step by Step
$mgh=\frac{kx^2}{2}$
$(62kg)(9.8\frac{m}{s^2})(20.0m)=\frac{k(1.4m)^2}{2}$
$k=1.24\times10^4\frac{N}{m}$
a) $F=mg=kx$
$F=(62kg)(9.8\frac{m}{s^2})=(1.24\times10^4\frac{N}{m})x$
$x=0.049m$
b) $E=mgh=\frac{kx^2}{2}$
$(62kg)(9.8\frac{m}{s^2})(38m)=\frac{(1.24\times10^4\frac{N}{m})x^2}{2}$
$x=3.72m$
