The Big Bang Theory allows scientists to extrapolate back in time and conclude that the universe __. Select all that apply. a) consisted of one star with eight orbiting planets b) emerged from a very tiny region and expanded c) consisted primarily of iron and nickel in the past d) was hotter and denser in the past e) consisted primarily of carbon and oxygen in the past f) was cooler and less dense in the past

Which of the following is considered to be a vector?               a.  temperature    b.  velocity    c.  time    d.  mass

10 newton object is placed 3 meters from the fulcrum. at what distance on the other side would you need to place a 15 newton object to balance the lever? show your work!

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. in a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina.with the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 2.05cm in front of the eye.)