The sound intensity level of a horn is 80dB. What is the sound intensity? The threshold of sound is 1x10-12W/m2.

1.0x10^-4 W/m^2 as sound intensity

Explanation:

Using

dB= 10log( I/Io)

Where Io= 10^-12W/m²

So dB=80dB

80= 10log(I/10^-12)

So

80/10= log (I/10^-12)

8= log (I/10^-12)

Taking the definition of log

10^8 = I/10^-12

I= 10^8 x10^ -12

I= 10^-4W/m² as sound intensity

The sound intensity is 1 x 10⁻⁴ W/m²

Explanation:

Given;

sound intensity level, β = 80 dB

The threshold of sound or threshold intensity of hearing, I₀ =  1 x 10⁻¹² W/m²

Sound intensity level is given as;

where;

β is the intensity level (dB)

I₀ is threshold intensity of hearing (W/m²)

I is the sound intensity (W/m²)

Therefore, the sound intensity is 1 x 10⁻⁴ W/m²

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.