Atired physics professor can easily read the fine print of the financial page when the newspaper is held at arm's length, 61.5 cm from the eye. what should be the focal length of an eyeglass lens that will allow him to read at the more comfortable distance of 26.0 cm?

The two required components for a generator are

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s

Which of the following is a measure of the amount of light a star directly emits?               a.  luminosity    b.  intensity    c.  wavelength    d.  brightness