How many arcseconds are in one arcminute?

Which of the following things is an “extended object”? For each item, answer “A” if the item is an acceptable extended object, “B” if the definition of an extended object applies badly to the item, and “D” if it is debatable.

(a) An electron (b) An atom (c) A rock (d) A swarm of bees (e) The earth’s atmosphere (f) The water in an ocean current (g) Sugar molecules dissolved in a cup of water (h) The vacuum between galaxies

The latest observations suggest the ratio of matter to energy is about

A) 24/73. B) 24/76. C) 3/24. D) 27/73. E) 3/97.

Two very flat glass plates, 16 cm long, are in contact at one end and separated by 0.020 mm at the other end. The space between the plates is occupied by oil with index of refraction 1.45. The refractive index of the glass plates is 1.55

The plates are illuminated at normal incidence with monochromatic light, and fringes are observed. When the monochromatic light has a wavelength of 580 nm, how many bright fringes are visible in the pattern? A) 60 B) 70 C) 80 D) 90 E) 100

A particle moves at a constant speed in a circular path with a radius of 2.06 cm. If the particle makes four revolutions each second, what is the magnitude of its acceleration?

a. 20 m/s2 b. 18 m/s2 c. 13 m/s2 d. 15 m/s2 e. 24 m/s2