4. an object (object a) with a mass of 500 kg is traveling in a straight line from west to east at a constant velocity of 34 m/s. object a encounters a headwind blowing with a force of 25 n for six minutes and then proceeds to collide with a stationary object (object b) with a mass of 300 kg, thereby reducing the velocity of object a to 4 m/s. what is the final velocity of object b?

that will be 500 + 34 + 25n(6) for a

and b 300/4

and it will equal 609

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.