английский
86. Change the sentence from Direct into Indirect / Reported Speech.
She said: “I lived in Poland when I was a child”.
Ann said: “I was speaking on the phone when the doorbell rang.”
98. Write the suitable ward to the definition.
are the result of prolonged rainfall from a storm.
are rain drops that have formed together into ice.
99. Rewrite the sentence in the Future Perfect tense form.
My mother will prepare a delicious meal tomorrow.
We’ll learn all the materials in this book.
100. Open the bracket and use the verb in the Present Continuous Tense Form.
The people …….. (To try) to solve the problem for a year.
My father ……… (To work) for this company since 2011.
Так как массы проводников одинаковые, то объем тоже одинаковый.
При S₁ = n*S₂ получим:
V₁ = V₂
S₁L₁ = S₂L₂
S₁/S₂ = L₁/L₂
n*S₂/S₂ = L₁/L₂
n = L₁/L₂
Таким образом:
R₁ = ρL₁/S₁
R₂ = ρL₂/S₂ => R₁/R₂ = L₁/L₂ * S₂/S₁ = n * 1/n = 1
То есть при одинаковых массах и материале сопротивление стержней с разной площадью поперечного сечения будет одинаковым потому, что насколько больше площадь сечения проводника, настолько меньше его длина при постоянном объеме.
Дано: СИ Решение
η = 85% η = Ап / Аз * 100%
m = 200кг Ап = mgh
h = 60см | 0.6м | Аз = Fl
F = 600Н l = mgh * 100% / ηF
l = 200кг * 10Н/кг *
0.6м * 100% /
l - ? 85% * 600Н = 2.35м