A disc of 8.0 cm in radius rotates at a constant rate of 1200 revolution per minute about its central axis. Calculate the
(a) angular velocity in rad s?

(b) tangential speed at a point 3.0 cm from its centre.

(c) distance travelled by a point at the edge of the disc in 2.0 s.

(d) angular acceleration if the disc stop rotating at 3.0 s.

Arotating space station is said to create “artificial gravity”—a loosely-defined term used for an acceleration that would be crudely similar to gravity. the outer wall of the rotating space station would become a floor for the astronauts, and centripetal acceleration supplied by the floor would allow astronauts to exercise and maintain muscle and bone strength more naturally than in non-rotating space environments. if the space station is 200 m in diameter, what angular velocity would produce an “artificial gravity” of 9.80 m/s^{2} 2 at the rim?

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. which one, if either is correct? a. beryl, because low thermal conductivity results in low heat transfer. b. beryl, because low thermal conductivity results in high heat transfer. d. sapphire, because low thermal conductivity results in high heat transfer. e. neither, because low heat transfer is desirable both in summer and in winter.

What is the relationship between wavelength of light and the quantity of energy per photon?