Question

Va rog urgent!!!
Dau coroana

Answer 1

5)Se da:
a)U=12V
L=36J
q=?C

b)t=4s
q=2C
I=?A

Formule:
a)Este o formula generala U=L/q, de unde q=L/U, daca nu stii asa formula atunci:
L=U*I*t

q=I*t

L=U*q
q=L/U

b)q=I*t
I=q/t

Calcule:
a)q=36/12=3C
b)I=2/4=0,5A

Raspuns: c) si a)

6)Se da:
m=120t=120000kg=12*10⁴kg
S=7cm²=7*10⁻⁴m²
U=380V
P=10kW=10⁴W
p=8900kg/m³
p'=1,7*10⁻⁸Ωm
a)l'=?m
b)R=?Ω
c)t=2h=7200s; L=?J
d)q=?C
e)I=?A

Formule:
a)m=V*p
m=S*l'*p
l'=m/S*p

b)R=p'*l'/S

c)L=U*I*t
L=t*U²/R

d)L=U*I*t
L=U*q
q=L/U

e)q=I*t
I=q/t

Calcule:
a)l'=12*10⁴/7*10⁻⁴*8900≈1,93*10⁴
b)R=1,7*10⁻⁸*1,93*10⁴/7*10⁻⁴≈0,47Ω
c)L=7200*380²/0,47=2212085106,4J
d)q=2212085106,4/380=5821276,6C
e)I=5821276,6/7200=808,51A