3) h=2 м vo=10 м/с α=?
===
h=vo²*sin²α/(2*g)
sinα=√(2*g*h)/vo=√(2*10*2)/10=0.632
α=arcsin0.632≈40°
====================
6) m=2 кг V=0.1 м³ M=0.044 кг/моль n=?
===
n=N/V=m*Na/(M*V)=2*6*10^23/(0.044*0.1)=2.73*10^26 [1/м³]
===============================