228 88Ra ^{228}_{\ 88}{\rm Ra} then decays through a series of beta-minus decays; eventually, another isotope of thorium,

228 90Th ^{228}_{\ 90}{\rm Th} , is formed. How many beta-minus decays will occur during this chain process?

Ben(55 kg) is standing on very slippery ice when junior(25kg) bumps into him. junior was moving at a speed of 8m/s before the collision and ben and junior embrace after the collision. find the speed of ben and junior as they move across the ice after the collision .

Need this now! do pilots live long

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.