A14-ft3 tank contains oxygen initially at 14.7 psia and 80°f. a paddle wheel within the tank is rotated until the pressure inside rises to 20 psia. during the process 20 btu of heat is lost to the surroundings. determine the paddle-wheel work done. neglect the energy stored in the paddle wheel. the gas constant and molar mass of oxygen are r = 0.3353 psia·ft3/lbm·r and m = 32 lbm/lbmol. the specific heat of oxygen at the average temperature of tavg = (735 + 540)/2 = 638 r is cv ,avg= 0.160 btu/lbm·r.

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.

a person with a mass of 106kg has a weight of 1060n

which piece of furniture will have the most inertia and give the furniture movers the most difficulty in moving?  

answer

a 75kg dining table