Perhaps the greatest of the Greek astronomers, Hipparchus compiled the first catalog of stars, 49) accurately measured their positions, and defined the basic system of stellar brightnesses which we now call the magnitude system. A particular star in his catalogue has an apparent magnitude of 4 and an absolute -12. Determine the distance to the star.

Three point charges, two positive and one negative, each having a magnitude of 20 μc are placed at the vertices of an equilateral triangle (30 cm on a side). what is the magnitude of the electrostatic force on the negative charge

High schoolphysics 5+3 pts a neon light consists of a glass tube with metal wires at each end. when connected to a high-voltage source, the gas glows. if a fly lands on the glass tube, what will most likely happen? a) the fly will not feel a shock because the glass conducts any free electrons back into the gas. b) electrons will flow directly from the metal wires along the glass and shock the fly. c) the fly will not feel a shock because the glass insulates it from the electrons in the gas and the metal. d) electrons that are moving through the gas will be conducted through the glass and shock the fly.

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?