An electronic point source emits sound isotropically at a frequency of 2 × 10^3 hz and a power of 27 watts. a small microphone has an area of 0.77 cm^2 and is located 3.5 meters from the point source. 1) what is the sound intensity at the microphone ? 2) what is the power intercepted by the microphone? 3) how many minutes will it take for the microphone to receive 0.2 joules from the sound waves? 4) what is the sound intensity level at the microphone from this point source? 5) what would be the sound intensity level at the microphone if the point source doubled its power output?

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.

the answer would be 32*f

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000