Two charged pith balls are suspended on very light 120 cm strings. Each has a mass of 10.0 g. Assume the angle the threads make from the vertical is θ = 15o and that the balls are in equilibrium. Draw a free-body diagram for one of the pith balls and clearly label all forces with magnitude and direction. Assuming the pith balls are equally charged, what is the charge on each ball?

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 maxium height is 34m/s

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach