A60-kg uniform board 2.4 m long is supported by a pivot 80 cm from the left end and by a scale at the right end (see the fig. below). (a) how far from the left end should a 40-kg child sit for the scale to read zero? (b) where should the child sit if the scale is to read (i) 100 n and (ii) 300n?

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) =_