for uniform motion v t graph is a straight line parallel to the
time co coordinating axis
for the x t graph it is a straight line through the origin making 45° with the x-axis
a liquid drop of diameter 4 miliimeter is given a charge of 2×10
magnet can, like any object with a mass, exert gravity force on different objects, regardless of their magnetic properties. same goes for electric force if magnet is charged and mechanical force. the latter can be easily observed when a magnet falls on somebody's foot ( is, in most cases, non-magnetic).