RÄspuns: Ļ = 1,37 g /cmĀ³
ExplicaČie:
Se amesteca mase egale din doua substante cu densitatile
Ļā = 1,2 g /cmĀ³ si Ļā = 1,6 g /cmĀ³. Se cere densitatea amestecului rezultat.
densitatea = masa : Volum
Ļ = m : V
Amestecul are masa mā = mā + mā .Si volumul V = Vā + Vā.
Volumul Vā = mā / Ļā si Vā = mā / Ļā
Adunam cele doua volume :
V = mā / Ļā + mā / Ļā = ( māĻā + māĻā ) / ĻāĻā
Dar cele doua substanČe au mase egale, deci mā = mā = m
V = ( māĻā + māĻā ) / ĻāĻā = m ( Ļā + Ļā) / ĻāĻā =
Calculam densitatea amestecului :
Ļ = mā : V = 2m : m ( Ļā + Ļā) / ĻāĻā = 2 ĻāĻā / (Ļā + Ļā)
Ļ = 2 x 1,2 x 1,6 : 2,8 = 1,37 g /cmĀ³
