Решить. при уменшении длины спиральной пружины на 3, 5 см возникает сила , равная 1, 4 кн. как велика силы пружины при уменшении её длины на 2, 1 см?

дано:

∆х1 = 3,5 см

∆х2 = 2,1 см

f1 = 1,4 кн

f2 - ?

 

решение:

по закону гука f = k*∆х,  f1 = k*∆х1,  f2 = k*∆х2, f1/f2 =  ∆х1/∆х2, f2 = f1*∆х2/∆х1

f2 = 1,4*2,1/3,5 = 0,84 кн

Exercise 1 1. they often make sandwiches for lunch. 2. i am not study at the moment. 3. i never study at night. 4. she talks to her friends every day. 5. she is not talking to her friends at the moment. 6. we have lessons every day. 7. we are not having an english lesson now. 8. he usually plays with jim or henry. exercise 2 1. the telephone rang while i was having a hot shower. 2. when you phoned last night, i was reading a fantastic book. 3. mary and i saw henry while we were waiting for the bus this morning. 4. last night we were having dinner with friends when helen arrived. 5. while the teacher explained the problem, lisa was dropping her books.

H=0,6 м                  давление. оказываемое столбом жидкости: ρ₁=1000 кг/м³            вода: p₁=ρ₁gh=1000*10*0,6=6000 па. ρ₂=800 кг/м³              керосин: p₂=ρ₂gh=800*10*0,6=4800 па. ρ₃=13600 кг/м³          ртуть: p₃=ρ₃gh=13600*10*0,6=81600 па. g=10 н/кг                    морская вода; p=ρgh=1030*10*0,6=6180 па. ρ=1030 кг/м³           p₁-? p₂-? p₃-? р-?