1.
R=qL/s= 0,017 Ом·мм2/м.*100м/0.5 мм2 = 3.4 Ом
I=U/R= 6.8/ 3.4 =2 А
2.
m1=3 л = 3*10^-3 м3
m2=1.5 л = 1.5*10^-3 м3
T1= 10 С = 283 К
T2= 100 С = 373 К
T-?
вода Q1=cm1(T-T1)
кипяток Q2=cm2(T-T2)
Q1+Q2=0
cm1(T-T1) + cm2(T-T2) = 0
m1T -m1T1 + m2T -m2T2 = 0
m1T+m2T -( m1T1 + m2T2) = 0
T=(m1T1 + m2T2 )/(m1+m2)
T= (3*10^-3*283 +1.5*10^-3*373) / (3*10^-3 +1.5*10^-3)= 313 K
3.
I=U/R = 110 B/11 Ом =10 А
5.
I=U+10 B=(110+10)/11 = 11 A
4.
F=G*m^2/R^2
m=√(FR^2/G)=√(50*10^-6*100^2/6.673*10^-11)=86561.4 кг = 86.6 т
