The cork from a champagne bottle slip through the hands of the waiter opening it, moving with an initial velocity v=11.8 m/s at an angle of 76.4 degrees above horizontal. a diner is sitting a horizontal distance d away when this happens. assume the cork leaves the waiter's hands at the same vertical level as the diner and that the cork falls back to this vertical level when it reaches the diner randomized variables v_o = 11.8 m/s theta = 76.4 degrees a) calculate the time, t_d in seconds, for the cork to reach the diner b) reacting quickly to avoid being struck, the diner moves 2.00m

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.