Question

Am nevoie de ajutor va rog

Answer 1

Răspuns:

2.  L=24000J

3.  F=45N

Lu=225J

Lc=281.25J

Explicație:

2.  P=L/t

P=Fd/t=Fv

v=72km/h=20m/s

L/10=120x20

L=2400x10

L=24000J

3.  la scripetele fix F=R   R=G=mg, g=10N/kg

F=4.5x10=45N

Lu=Fh=45x5=225J

η=Lu/Lc

80/100=225/Lc

Lc=22500/80

Lc=281.25J