A far-sighted student has a near point of 322 cm. Calculate the focal length of the glasses needed so the near point will be normal (25 cm). Neglect the space between the eyes and the eye-glasses. Answer in units of cm.

If a stone with an original velocity of 0 is falling from a ledgeand takes 8 seconds to hoybthe ground whays the final velocity of the stone

The atoms in a nickel crystal vibrate as harmonic oscillators with an angular frequency of 2.3 × 1013 rad/s. the mass of a nickel atom is 9.75 × 10-26 kg. what is the difference in energy between adjacent vibrational energy levels of nickel? (h = 6.626 × 10-34 j • s, , 1 ev = 1.60 × 10-19 j)

Which of these statements best explains how the hydrosphere interacts with the atmosphere to affect global climate? mountains block rain clouds and cause changes in global rainfall and evaporation. humans burn fossil fuels to produce greenhouse gases which cause global warming. humans cut down trees which affects the amount of oxygen in different parts of the globe. greenhouse gases, like carbon dioxide, dissolve in oceans and prevent global warming.