Two identical tiny spheres of mass m =2g and charge q hang from a non-conducting strings, each of length l = 10cm. at equilibrium, each string makes and angle θ =50 with the vertical. find the size of the charge on each spere.

q = 7.88μC

Explanation:

In the diagram attached, you can visualize the situation. Separation distance between the 2 charges is:

D = 2*L*sin θ = 0.1532m

From a sum of forces on the X-axis:

And on the y-axis:

  Solving for T and replacing its value on the X-axis equation we get:

 Since

 Solving for q we get:

q = 7.88μC

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.