Physics, 29.11.2019 01:31 beaaaaast3

Aballoon filled with helium gas has an average density of rhob = 0.27 kg/m3. the density of the air is about rhoa = 1.23 kg/m3. the volume of the balloon is vb = 0.084 m3. the balloon is floating upward with acceleration a.

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Answer from: lovenahofer

34.84 m/s^2

Explanation:

Given

density of balloon $\rho _{He}=0.27 kg/m^3$

density of air $\rho _a=1.23 kg/m^3$

volume of balloon V=0.084 m^3

If balloon is rising then

F_b-mg=ma

where $F_b=buoyant\ Force=\rho _a\times V\times g$

$mg=\rho _{He}\times V\times g=weight of gas$

a=acceleration

$\rho _a\times V\times g-\rho _{He}\times V\times g=\rho _{He}\times V\times a$

$\rho _a\times g-\rho _{He}\times g=\rho _{He}\times a$

divide by $\rho _{He}$

$\frac{\rho _a}{\rho _{He}}\times g-g=a$

$a=g(\frac{\rho _a}{\rho _{He}}-1)$

$a=g(\frac{1.23}{0.27}-1)$

$a=3.55\times 9.8$

a=34.84 m/s^2

Answer from: Quest

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.

$_a^z\textrm{x}\rightarrow _{a-2}^{z-4}+_2^4\alpha$

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.

$_a^z\textrm{x}+_{-1}^0\textrm{e}\rightarrow _{z-1}^a\textrm{y}$

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 $\gamma -radiations$ . this process does not change the mass number.

$_a^z\textrm{x}^*\rightarrow _a^z\textrm{x}+_0^0\gamma$

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 $\beta ^+$ -decay. in this the mass number remains same.

$_a^z\textrm{x}\rightarrow _{z-1}^a\textrm{y}+_{+1}^0e$

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

Answer from: Quest

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