Question

O macara cu puterea 8.82 kW a ridicat un corp cu masa 4.5 t la o inaltime de 8 m. In cat timp a facut aceasta lucrare? Se da g=9.8 N/kg

Answer 1

P=8,82 kW=8820 W
m=4,5 t=4500 kg
h=8 m
g=9,8 N/kg
t=?
t=L/P
L=F·d
F=G
G=m·g
G=4500 kg·9,8 N/kg
G=44100 N
F=44100 N
d=h
d=8 m
L=44100 N·8 m
L=352800 J
t=352800 J/8820 W
t=40 s.