Radioactive decay of unstable atomic nuclei is a fi rst-order process. th e half-life for the (fi rst-order) radioactive decay of 14c is 5730 a (1 a is the si unit 1 annum, for 1 year; the nuclide emits b particles, high-energy electrons, with an energy of 0.16 mev). an archaeological sample contained wood that had only 69 per cent of the 14c found in living trees. what is its age?

What is the kinetic energy of a baseball moving at a speed of 40 m/s if the baseball has mass of 0.15 kg?

Acapacitor is storing energy of 3 joules with a voltage of 50 volts across its terminals. a second identical capacitor of the same value is storing energy of 1 joule. what is the voltage across the terminals of the second capacitor?

An ideal otto cycle has a compression ratio of 8. at the beginning of the compression process, air is at 95 kpa and 27°c, and 750 kj/kg of heat is transferred to air during the constant-volume heat-addition process. assuming constant specific heats at room temperature, determine (a) the pressure and temperature at the end of the heat-addition process, (b) the net work output, (c) the thermal efficiency, and (d) the mean effective pressure for the cycle. (4390 kpa, 1730 k; 423 kj/kg; 56.4%; 534 kpa)