**I need theses answered by 9:30*** a 9.0-kg dog runs at 4.0 m/s and jumps onto a stationary skateboard the mass of the skateboard is 1.0 kg what speed is the speed of the skating dog?
1. before the dog jumps onto the skateboard
what is the momentum of the dog?
what is the momentum of the skateboard?
2. after the dog jumps onto the skateboard
a. what is the momentum of the dog?
b. what is the momentum of the skateboard?

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.

did yall get answers for this yet