A 60co source is labeled 4. 00 mci, but its present activity is found to be 1. 85×107 bq. (a) what is the present activity in mci? (b) how long ago did it actually have a 4. 00-mci activity?.

A10nc charge sits at a point in space where the magnitude of the electric field is 1500 n/c. what will the magnitude of the field be if the 10 nc charge is replaced by a 20 nc charge? assume the system is big enough to consider the charges as small test charges.

Find the mass by adding the numbers from the three sliders

Of is j/kg·k. if a 2.6 kg of isk to k,is ?