016 (UMC-SP) Um aluno do curso de engenharia mecânica da UMC deseja medir a temperatura de um forno utilizando uma barra metálica de comprimento igual a 1 m, que se encontra inicialmente a 22 °C. A barra é introduzida no forno e, ao ser retirada, o aluno verifica que o seu comprimento passa a ser 1.01 m. Sabendo que a variação de comprimento (/L) é diretamente proporcional à variação de temperatura (/t) e ao comprimento inicial (L0), pede-se determinar a temperatura do forno, Dado: Coeficiente de dilatação linear do metal 10. 10-6

Antireflective coatings on solar cells are often made by applying a thin film of silicon nitride (sinx), which has an index of refractive of 1.2, on the top of the silicon solar cell, which has a refractive index of about 3.5. however, the sun emits radiation of various wavelengths which the solar cell absorbs, and the antireflective coating can only absolutely minimize the reflection of one of these wavelengths. the coating thickness is chosen to reduce the reflection of green/yellow light (e = 2.2 ev), which is the most intense color in the solar spectrum (shown below). which of the following coatings would minimize reflection of green/yellow light? the answer is 820 nm how? what is the angular width of the central maximum of an electron traveling at 2 x 108 m/s going through a single slit of width 1 mm.