A burglar attempts to drag a 105 kg metal safe across a polished wood oor Assume that the coecient of static friction is 0.4, the coecient of kinetic friction is 0.3, and that the burglar can apply a pushing force of 520 N on the metal safe. What is the acceleration of the metal safe across oor?

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=