A10.0 kg dog chasing a rabbit north at 6.0 m/s has a momentum of
0.6 kg m/s.
60.0 kg/s
60.0 m/s.
60.0 kg*m/s north.

 60.0 kg*m/s north.

Explanation: The linear momentum is a verctor, it has magnitude and direction. Also the momentun is proportional to the mass multiplier the velocity.

P=m*V ( vector)

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.