Given that the total area of contact of shoes and the floor is 0.02m2,determine the mass of the girl

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?

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.

Acentrifuge in a medical laboratory rotates at an angular speed of 3,700 rev/min. when switched off, it rotates through 54.0 revolutions before coming to rest. find the constant angular acceleration (in rad/s2) of the centrifuge. your response is within 10% of the correct value. this may be due to roundoff error, or you could have a mistake in your calculation. carry out all intermediate results to at least four-digit accuracy to minimize roundoff error. rad/s2