Question

ex 2 va rog dau coroana URGENT!! dau test maine

Answer 1

η=70%

m=1400kg

h=20m

η=$\frac{L_U}{L_C}$

$L_C=\frac{L_U}{randament}$

L_U=mgh=28kJ

$L_C=\frac{28000}{\frac{70}{100} }=\frac{28000*100}{70}=40000 J= 40kJ$