Science ! asap : )

kevin ties a string to a marble and swings it around his head. he then cuts the string suddenly and watches as the marble continues traveling in a straight line.

which correctly explains what happened?

a.
centrifugal force directed away from the center of the circle causes the marble to continue moving perpendicular to the circle.

b.
centripetal force directed at the center of the circle causes the marble to continue moving tangent to the circle.

c.
centrifugal force directed at the center of the circle causes the marble to continue moving parallel to the circle.

d.
centripetal force directed away from the center of the circle causes the marble to continue moving adjacent to the circle.

When you turn on a battery-operated device, an electrical circuit is

Which of the following are not typically included in the periodic table? a. atomic mass b. element symbol c. isotopes d. number of electrons

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.