The half life of uranium-235 is 4.5 billion years. If 0.5 half-lives have elapsed, how many years have gone by?

Diamond will scratch quartz. true or false

An object's buoyant force and weight mean the same thing. a. trueb. false

In the circuit, the switch s has been open for a long time and r = 125 kohm. it is then suddenly closed. (a) determine the time constant before the switch is closed. s (b) determine the time constant after the switch is closed. _ s (c) let the switch be closed at t = 0. find the current in the switch as a function of time. (use t for time. express your answer in milliamps and seconds.) i(t) =_