It is science time! you and your classmates have been challenged to identify six minerals. you begin with a dull, white sample that is easily scratched with a fingernail. what is the mineral?

Aplanet of mass m 6.75 x 1024 kg is orbiting in a circular path a star of mass m 2.75 x 1029 kg. the radius of the orbit is r 8.05 x107 km. what is the orbital period (in earth days) of the planet tplanet?

An asteroid is discovered in a nearly circular orbit around the sun, with an orbital radius that is 2.47 times earth's. what is the asteroid's orbital period, its "year," in terms of earth years?

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?