Aroller coaster takes energy to make the first rise, but then it should be able to run the course of the track without any input of energy. this, however, is not true. energy continues to be needed. this is because some of the energy is converted to sound energy, and some is given off as heat energy. this is a good example of which law?

the first law of thermodynamics
the second law of thermodynamics
the third law of thermodynamics
the zeroth law of thermodynamics

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.