13

13-2
$E_p=mgh$
$m=55kg$
$g=9{,}81\ \frac{m}{s^2}$

a)
$h=8848m$
$E_p=4{,}7739...\cdot10^6J\approx4{,}8MJ$
b)
$h=-10994m$
$E_p=-5{,}9318...\cdot10^6J\approx5{,}9MJ$

13-5
$E=mg\Delta h$
$m=1{,}9\cdot10^5kg=190000kg$
$g=9{,}81\ \frac{m}{s^2}$
$\Delta h=10{,}70km=10700m$
$E=1{,}99437...\cdot10^{10}J=19{,}9437...GJ\approx20GJ$