A force of 52N acts upon a 4kg block sitting on the ground. Calculate the acceleration of the object.​

It is really hard for me right know

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.

During the refrigeration cycle, what does the refrigerant do? absorbs and releases thermal energy by first vaporizing then condensing. absorbs and releases thermal energy by first condensing then vaporizing. insulates the thermal energy away from the cooling area. transfers thermal energy to the cooling area by condensing.